Interior Monologue (Young Adult).

Interior Monologue is the fancy literary term for a character’s thoughts in a work of fiction.

The literary technique of Interior Monologue is closely related to––or perhaps based on––the psychological phenomenon of Internal Monologue, also called self-talk or inner speech. 

This is a person’s inner voice which provides a running verbal monologue of thoughts while they are conscious.

It is usually tied to a person’s sense of self, and the development of this sense in children is tied to the development of language.

It is particularly important in planning, problem solving, self-reflection, self-image, critical thinking, emotions, and subvocalization (silent reading). 

In some cases people may think of inner speech as coming from an external source, as with schizophrenic auditory hallucinations. 

Interestingly, it’s reported that not everyone has verbal internal monologue, and for most people the voice of internal monologue pauses for at least some of the time.

There have been studies done on pre-verbal children, in which it seems there’s a pre-verbal (or mentalese) interior monologue.

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While we’re dealing with definitions, a couple of closely-related literary terms are… 

  • Stream of Consciousness. This is where an entire novel, or at least large chunks of it, takes the form of the central character’s thoughts. Such novels tend to be light on plot, so I wouldn’t necessarily recommend this device.

Here is an excerpt from the Bell Jar, by Sylvia Plath.

(In this scene, the protagonist, Esther, has gone on a swing trip with her sometime boyfriend, Buddy. Notice how the narration starts out with scenic information, then transitions into stream-of-consciousness, then back to scene) :

Buddy had never skied before either, but he said that the elementary principles were quite simple, and as he’d often watched the ski instructors and their pupils he could teach me all I’d need to know.
For the first half hour I obediently herringboned up a small slope, pushed off with my poles and coasted straight down. Buddy seemed pleased with my progress.
“That’s fine, Esther,” he observed, as I negotiated my slope for the twentieth time. “Now let’s try you on the rope tow.”
I stopped in my tracks, flushed and panting.
“But Buddy, I don’t know how to zigzag yet. All those people coming down from the top know how to zigzag.”
“Oh, you need only go halfway. Then you won’t gain very much momentum.”
And Buddy accompanied me to the rope tow and showed me how to let the rope run through my hands, and then told me to close my fingers round it and go up.
It never occurred to me to say no.
I wrapped my fingers around the rough, bruising snake of a rope that slithered through them, and went up.
But the rope dragged me, wobbling and balancing, so rapidly I couldn’t hope to dissociate myself from it halfway. There was a skier in front of me and a skier behind me, and I’d have been knocked over and stuck full of skis and poles the minute I let go, and I didn’t want to make trouble, so I hung quietly on.
At the top, though, I had second thoughts.
Buddy singled me out, hesitating there in the red jacket. His arms chopped the air like khaki windmills. Then I saw he was signaling me to come down a path that had opened in the middle of the weaving skiers. But as I poised, uneasy, with a dry throat, the smooth white path from my feet to his feet grew blurred.
A skier crossed it from the left, another crossed it from the right, and Buddy’s arms went on waving feebly as antennae from the other side of a field swarming with tiny moving animalcules like germs, or bent, bright exclamation marks.
I looked up from that churning amphitheater to the view beyond it.
The great, gray eye of the sky looked back at me, its mist-shrouded sun focusing all the white and silent distances that poured from every point of the compass, hill after pale hill, to stall at my feet.
The interior voice nagging me not to be a fool—to save my skin and take off my skis and walk down, camouflaged by the scrub pines bordering the slope—fled like a disconsolate mosquito. The thought that I might kill myself formed in my mind coolly as a tree or a flower.
I measured the distance to Buddy with my eye.
His arms were folded, now, and he seemed of a piece with the split-rail fence behind him—numb, brown and inconsequential.
Edging to the rim of the hilltop, I dug the spikes of my poles into the snow and pushed myself into a flight I knew I couldn’t stop by skill or any belated access of will.
I aimed straight down.
A keen wind that had been hiding itself struck me full in the mouth and raked the hair back horizontal on my head. I was descending, but the white sun rose no higher. It hung over the suspended waves of the hills, an insentient pivot without which the world would not exist.
A small, answering point in my own body flew toward it. I felt my lungs inflate with the inrush of scenery—air, mountains, trees, people. I thought, “This is what it is to be happy.”
I plummeted down past the zigzaggers, the students, the experts, through year after year of doubleness and smiles and compromise, into my own past.
People and trees receded on either hand like the dark sides of a tunnel as I hurtled on to the still, bright point at the end of it, the pebble at the bottom of the well, the white sweet baby cradled in its mother’s belly.
My teeth crunched a gravelly mouthful. Ice water seeped down my throat.
Buddy’s face hung over me, near and huge, like a distracted planet. Other faces showed themselves up in back of his. Behind them, black dots swarmed on a plane of whiteness. Piece by piece, as at the strokes of a dull godmother’s wand, the old world sprang back into position.
“You were doing fine,” a familiar voice informed my ear, “until that man stepped into your path.”
People were unfastening my bindings and collecting my ski poles from where they poked skyward, askew, in their separate snowbanks. The lodge fence propped itself at my back.
Buddy bent to pull off my boots and the several pairs of white wool socks that padded them. His plump hand shut on my left foot, then inched up my ankle, closing and probing, as if feeling for a concealed weapon.
A dispassionate white sun shone at the summit of the sky. I wanted to hone myself on it till I grew saintly and thin and essential as the blade of a knife.
“I’m going up,” I said. “I’m going to do it again.”
“No, you’re not.”
A queer, satisfied expression came over Buddy’s face.
“No, you’re not,” he repeated with a final smile. “Your leg’s broken in two places. You’ll be stuck in a cast for months.”

Here is another example from ‘In Darkness’ by Nick Lake. The Protagonist, 15 year-old Shorty, is stuck in total darkness in a destroyed hospital in Port au Prince, Haiti, following the recent earthquake. The chapters alternate between the reflections and hallucinations of the main character and the history of Haiti’s war of independence in the early 1800’s.

NOW

In the darkness I can’t tell when I’m dreaming and when I’m just thinking. I hear the dead hand beside me scrabbling, scrabbling at the floor. For a moment, I’m scared. Then I think, well, at least I’m not alone.

But I realize it was probably just the rat, come back to gnaw on the dead people again.

I see people coming through the walls, pulling the concrete apart with their bare hands, coming to rescue me. I’m pretty sure they’re not real cos I see them, and it’s not possible to see anything real in here – it’s too black. But they seem real, these people, with their strong hands and their smiling faces.

I’m hallucinating, I know this. Do I? I’m seeing shit that isn’t there. I’ve taken drugs before – everyone does in the Site – so I know what it feels like. Maybe I even dreamed those people calling?

My mouth has grown enormous again. Hours or days ago I had to pee and I collected the liquid in my hands, as much as I could, and I drank it.

Oh, Manman. Look at me now. You told me I would get what was coming to me.

At some point I close my eyes. Suddenly I’m drifting up, up through the half-fallen ceiling, the concrete flesh of the building skeletoned with rods of steel, and then further through floors upon floors of twisted metal and bodies, and then up into the sky. It’s light out here. I can see the hospital below me. It’s so broken that it doesn’t look man-made at all; it’s just a pile of random blocks.

I’m in the clouds. I think, maybe I am magical, maybe I am still Marassa, even if my sister is gone. In the Site, ever since we were born, people said we were special. They said we were Marassa, and that gave us powers to change the world. They said we had been given life by Aristide, and so the spirit of the people and the revolution was in us.

Even after Marguerite was taken from us, people said these things. They said that Dread Wilmè had died to protect my life, so all that rebellion had been made even stronger, like when you put carbon into iron and it makes it harder, makes it steel. Some even said that Dread Wilmè lived inside me, and they would look at me strangely as I walked down the street.

I thought that was stupid, but now I think, maybe it’s not so stupid after all.

I can see the whole of Port-au-Prince – the palace, the homes of the rich, the open-air prison of Site Solèy. It’s all collapsed. The palace is just dust and rubble, the homes are destroyed. Only Site Solèy looks the same, and that’s cos Site Solèy was a ruin to begin with.

There’s a gull beside me in the clouds. It peers at me, and banks and screams. I can see planes circling above the airport, and helicopters flying back and forth above the city. There are people crawling over the wrecked hospital below me, like little ants in hard hats.

Earthquake, I think, cos it’s the only thing that could smash everything up like this. When we were little, my sister and me, we would make cities out of the mud in the gutters of Site Solèy, and then we would say we were dinosaurs or earthquakes and stomp those cities to nothing.

The devastation I pictured in my head never got close to this, though. From above, Haiti looks like it’s been wiped off the earth by an angry god. Maybe Dread Wilmè was made into a zombi, and he’s come back to punish the land and has shaken everything to pieces in his anger.

I wonder if I can fly, and I try to bank toward the palace to get a better look. But I can’t move where I want. Suddenly I’m rising again, up, up among the clouds and then bursting through them, and it’s like the flattened city had never been there; I’m in clear blue sky above soft white clouds and it goes on forever.

Then I’m descending very fast. It’s night-time now, which seems strange and at the same time not strange. I must have flown far over the clouds, cos I’m not above the city, either; I’m looking down on marshland, dense with trees. There are no electric lights, though I can see a tentative, reddish light on the other side of the trees, flickering like bloody water, which must be torches or candles.

My speed increases. I’m breaking through the treetops now and I see that there are people below; they’re standing in a circle and looking very intently at a man who’s dancing and singing like a mad person. They turn from him and look at another man – he’s big and tall and wildly ugly, his nose sort of squashed and swollen. He’s leaning back, screaming, it seems to me, looking straight up at me as I hurtle downward. I just have time to see that he’s foaming at the mouth – he’s having some kind of fit – then his mouth is getting bigger and bigger, like mine did when I was so thirsty, and his mouth takes over the world, like mine did, contains it within its twisted and blackened teeth, its diseased gums, and I’m inside it and I’m sinking, sinking into the darkness.

  • Another technique related to interior monologue is the Soliloquy. This is where a fictional character voices his or her thoughts out loud, as in Hamlet’s “To be or not to be” speech. Talking aloud to yourself at any length is frankly strange, so always so always keep any interior monologue unspoken unless you have a good reason not to. In other words a soliloquy is going to be theatrical. Could work but will be an odd stylization. 

Here is the Soliloquy from Hamlet:

To be, or not to be–that is the question: 

Whether ’tis nobler in the mind to suffer 

The slings and arrows of outrageous fortune 

Or to take arms against a sea of troubles 

And by opposing end them. 

To die, to sleep– No more–and by a sleep to say we end 

The heartache, and the thousand natural shocks 

That flesh is heir to. ‘Tis a consummation 

Devoutly to be wished. To die, to sleep– 

To sleep–perchance to dream: ay, there’s the rub, 

For in that sleep of death what dreams may come 

When we have shuffled off this mortal coil, 

Must give us pause. There’s the respect 

That makes calamity of so long life. 

For who would bear the whips and scorns of time, 

Th’ oppressor’s wrong, the proud man’s contumely 

The pangs of despised love, the law’s delay, 

The insolence of office, and the spurns 

That patient merit of th’ unworthy takes, 

When he himself might his quietus make 

With a bare bodkin? Who would fardels bear, 

To grunt and sweat under a weary life, 

But that the dread of something after death,

 The undiscovered country, from whose bourn 

No traveller returns, puzzles the will, 

And makes us rather bear those ills we have 

Than fly to others that we know not of? 

Thus conscience does make cowards of us all, 

And thus the native hue of resolution 

Is sicklied o’er with the pale cast of thought, 

And enterprise of great pitch and moment 

With this regard their currents turn awry 

And lose the name of action. — Soft you now, 

The fair Ophelia! — Nymph, in thy orisons Be all my sins remembered…

So…back to Interior Monologue 

Okay, let’s start with the basics. The two varieties of interior monologue found in a novel are long ones and short ones. 

A short interior monologue tends to happen in the middle of a scene. Because scenes are generally characterized by talk and action, you don’t want to destroy the pace with too many lengthy thoughts from the viewpoint character.
That is why you tend to get just a line of thought here and there – enough to directly connect us to the viewpoint character’s mind, but not enough to disrupt the flow of the scene. 

All other clues about how the viewpoint character is feeling can be presented indirectly – that is, through their words, actions, facial expressions, and so on.
Here is an example of a short interior monologue from Nick Hornby’s novel Juliet, Naked. The viewpoint character, a man called Tucker, is having a talk with his son… 

Jackson was in his room, bashing the hell out of the buttons on a cheap computer game. He didn’t look up when Tucker opened the door.
‘You want to come back downstairs?’
‘No.’
‘It’ll be easier if the three of us talk.’
‘I know what you want to talk about.’
‘What?’

‘”Mummy and Daddy are having problems, so we’re going to split up from each other. But it doesn’t mean we don’t love you, blah blah blah.” There. Now I don’t have to go.’
Jesus, thought Tucker. Six years old and already these kids can parody the language of marital failure.
‘Where did you get all that from?’
‘Like, five hundred TV shows, plus five hundred kids at school. So that’s a thousand, right?’
‘Right. Five hundred plus five hundred makes a thousand.’
Jackson couldn’t prevent a tiny flicker of triumph crossing his face.
‘OK. You don’t have to come down. But please be kind to your mother.’ 

Here, we get one short paragraph of interior monologue (‘Jesus, thought Tucker. Six years old and already these kids can parody the language of marital failure.’)
It helps us to experience what it feels like to be standing there in the father’s shoes, but it doesn’t affect the pace of the scene significantly. If you re-read the passage but leave out the monologue, the effect is cooler and more distant.

A long interior monologue tends to happen during the slower bits in between action scenes. Here, a breakneck pace isn’t necessary, and so having direct access to the character’s every thought for a few sentences or paragraphs, or even a few pages, is not a problem. 

Also, it’s natural for a character to do the bulk of their thinking in between scenes… 

  • During the scene, they’re too busy doing things and saying things, and reacting to things being done and said to them, to have the time for a lengthy internal
    monologue. 
  • Once the scene is over and they can pause to draw breath, they have plenty of time for a good long think. Plus, of course, they will have plenty to think about, given that the scene just ended will probably not have gone according to plan, and they must now decide what to do next.
    I’m not saying that all “interludes” (the quiet moments in between scenes) consist of characters thinking. Sometimes an interlude can be a simple “Two days later…” But where you do have lengthy interior monologues in a novel, it’s generally better to have them in the calm period between scenes. 

Here is an example of a long interior monologue (or the very beginning of one), again from Nick Hornby’s novel Juliet, Naked… 

On the way to the airport, Jackson chatted about school, baseball and death until he fell asleep, and Tucker listened to an old R&B mix-tape that he’d found in the trunk. He only had a handful of cassettes left now, and when they were gone, he’d have to find the money for a new truck. He couldn’t contemplate a driving life without music. He sung along to the Chi-Lites softly, so as not to wake Jackson, and found himself thinking about the question that woman had asked him in her email: ‘It isn’t you really, is it?’ Well, it was him, he was almost positive, but for some reason… 

And off the character goes on a lengthy interior monologue…
Novel writers can keep these longer internal monologues going for several pages if necessary. You are not disrupting the flow of the narrative because not much is happening anyway (in this case, the character is simply driving and listening to music while his son sleeps beside him).
And that is all there is to it.
Any internal monologues in the middle of a scene will generally take the form of one- liners, while the internal monologues in the interludes can run on for pages.
Long monologues are easy to handle… 

• You start with some narration, just to show the reader what the character is doing (in the case of the example above, the character is driving and listening to music). 

• Then you launch into the monologue itself, perhaps introducing it with a phrase like “he thought about…” or “she wondered if…” (Hornby wrote that the character “found himself thinking about…”) 

Short, one-liner interior monologues in the middle of a scene are trickier, simply because you need to make it clear to the reader that this particular sentence, in the middle of all the talk and action, is indeed the viewpoint character thinking.
To do that successfully – like a professional novelist – you need to understand… 

Interior Monologue Mechanics 

Everything I’ve said about internal monologue so far has been useful (I hope!) but still kind of vague. What many novel writing students want to know is precisely how to portray a character’s thoughts on the printed page – should they use italics, for example, or a “he thought” tag? 

So what is the best way to indicate that a sentence or two of interior monologue in the middle of a scene is the viewpoint character’s thoughts (and not the narrator narrating)? 

Here are the possibilities open to you… 

  1. Writing the thought in first person, present tense (which is the way we actually think them) vs. writing it in third person, past tense (so that they blend in with the rest of the text). 
  2. Using italics vs. using normal text. 
  3. Using a “he thought” tag vs. not using one. 
  4. Wrapping the thought in quotation marks (either single or double) vs. not using
    quotation marks.

We can dispense with the final option straight away: Never use quotation marks around a character’s thoughts. Why?
Because the reader will assume the words are being said out loud, and will then have to make an awkward mental shift when they see a “he thought” interior monologue tag, rather than a “he said” dialogue tag, at the end.
We can also dispense with using italicized text when the thought is translated into third person past tense.
The only point of italics is to make a different voice and tense stand out from the regular voice and tense being used. When both the thought and the text surrounding it are in the same voice and tense there is no need for italics. 

What we are left with, then, are six possibilities… 

1. Thought written in first person present, italicized, tagged 

Mary closed her eyes and lifted her face to the sun. This summer has been so perfect, she thought. I don’t want it ever to end. 

2. Thought written in first person present, italicized, not tagged 

Mary closed her eyes and lifted her face to the sun. This summer has been so perfect. I don’t want it ever to end. 

3. Thought written in first person present, not italicized, tagged 

Mary closed her eyes and lifted her face to the sun. This summer has been so perfect, she thought. I don’t want it ever to end. 

4. Thought written in first person present, not italicized, not tagged 

Mary closed her eyes and lifted her face to the sun. This summer has been so perfect. I don’t want it ever to end. 

5. Thought written in third person past, not italicized, tagged 

Mary closed her eyes and lifted her face to the sun. This summer had been so perfect, she thought. She didn’t want it ever to end. 

6. Thought written in third person past, not italicized, not tagged 

Mary closed her eyes and lifted her face to the sun. This summer had been so perfect. She didn’t want it ever to end.

 

Which of these possibilities is best? 

You’ll find examples of all of the above in published fiction, so in a sense it’s a matter of personal choice. The only hard and fast rule that exists is to be consistent throughout… 

Whatever method of presenting monologue you use in the first chapter – first person present and italicized text, for example – you should still be using it in the final chapter. 

Readers quickly grow accustomed to whatever conventions you use, and not sticking to those conventions throughout will only confuse your audience. 

So is it simply a question of choosing a way to present interior monologue, and then sticking with it? 

Not exactly, no. And it’s not a question of one method being “better” than the others, either. 

So I’ll now run through the advantages and disadvantages of all the ways of presenting interior monologue, then leave it up to you to decide which way is best for your own novel. I’ll start by answering this question… 

Should a Character’s Thoughts Be Italicized? 

Italics, as I have said, are used to represent a character’s thoughts as they actually think them in their head (i.e. the precise words they use). For that reason, italicized thoughts are always written in… 

  • First Person – because we don’t think about ourselves in the third person.
  • Present Tense – because we don’t think about what is happening now in past tense. (Obviously, we sometimes think in the third person past tense, when we think about what somebody else did yesterday, for example: “John made such a fool of himself last night.”) The advantage of using italics for a line or two of interior monologue is that they make the thought stand out.
    It will be perfectly obvious to the reader that these words are the character thinking, and not the author narrating. And the thought itself, as well as not becoming confused with the rest of the text, gains an extra emphasis, like in this example from Clare Morrall’s The Man Who Disappeared.
    Felix, a man whose world has just fallen apart, is standing out in the street watching his family eat their evening meal without him…

He wants to believe in this cosiness, this world of families, this labyrinth of deeply entwined love.
That’s the key, of course: love. He has been told this for as long as he can remember. ‘We love you, Felix,’ one of his aunts used to say, ‘and that’s all that matters.’
What have I done, Kate?
Frost glints on the road, nearby car windscreens are clouded with ice. Felix blows on his hands and shuffles his feet around, trying to bring some feeling back to his toes.

The trouble with using italics for character thoughts is that they can be tedious to read. If you use italics for every single thought in the novel, not just the one-liners but the longer ones that run for several paragraphs or pages, the reader won’t thank you for it.
Also, because italicizing interior monologue gives the words much greater weight and emphasis, the effect you create could turn out to be unintentionally comic. 

The italicized thought in the example above – “What have I done, Kate?” – is worthy of emphasis. It has even been given a paragraph all to itself (which is another way of making interior monologue stand out). But this device would be totally inappropriate for more mundane character thoughts… 

  • What a beautiful morning 
  • I wonder what’s for lunch 
  • I left my wallet at home
  • The solution, if you want to use italicized thoughts in the first person present, is to use them very sparingly. Only write a character’s most important and moving thoughts in this way. For the rest, use a more subtle method of presenting internal monologue, like non- italicized third person thoughts.
    Clare Morrall did precisely that in the example above…
  • The first two paragraphs are pure interior monologue, but they are written in the third
    person. (The only reason they are written in the present tense is that the entire novel
    is; otherwise, they would be in the past tense.)
  • In the third paragraph, she uses first person present tense and italics.
  • The fourth paragraph is regular narration.

The entire extract could have been written like this (with all three paragraphs of interior monologue italicized)… 

I want to believe in this cosiness, this world of families, this labyrinth of deeply entwined love. 

That’s the key, of course: love. I have been told this for as long as I can remember. ‘We love you, Felix,’ one of my aunts used to say, ‘and that’s all that matters.’ 

What have I done, Kate? 

Frost glints on the road, nearby car windscreens are clouded with ice. Felix blows on his hands and shuffles his feet around, trying to bring some feeling back to his toes. 

… but in my opinion, the passage would not have been half as effective.
Doesn’t using first person italicized thoughts for some of the time, and third person non- italicized thoughts for the remainder, contradict my earlier advice about remaining consistent?
Nope. The “convention” you would have decided on would be to use… 

  • Third person non-italicized thoughts for the bulk of the interior monologue, and
  • First person italicized thoughts in just a handful of places, when the power of the
    character’s words demand extra emphasis.
    The reader will quickly pick up on this convention if you use it consistently. What they would find confusing would be if you used, for example, an illogical mixture of italics and non-italics for those occasional emphatic thoughts. 

One last thing before moving on… 

  • If you do use this device of writing the occasional powerful thought in the first person present, you really should use italics if you don’t want to confuse the reader, and ideally a separate paragraph too. This makes the first person thought stand out clearly from the surrounding third person text.
  • Next best, if you don’t use italics, is to add a “he thought” tag to the words.
  • And the least emphatic of all is to use neither italics nor thought tags. Just to be clear on that, here are those three options:
    What have I done, Kate?
    What have I done, Kate? he thought. What have I done, Kate?
    If you want to emphasize the character’s thought, use the first option. If, for whatever reason, you want to take a more subtle approach, use the second or third.
    Now for a closer look at…

Interior Monologue Tags 

“Thought” tags are exactly like the ones you use in dialogue – their only real purpose is to make it clear to the reader who is speaking or, in the case of thought tags, that these are the character’s thoughts and not the narrator’s words.
If everything is crystal clear without using a tag – either in monologue or dialogue – don’t use one. 

For example, in the case of those italicized, first person thoughts I discussed above, using a tag (What have I done, Kate? he thought) is totally unnecessary. It’s obvious that these words are coming straight from the character’s head.
If a thought is written in the third person, it may or may not be advisable to use a tag. It all depends on where the “camera” is positioned… 

I talked about cameras in the article on Writing In the Third Person. Here is the theory in a nutshell… 

  • At the start of a scene in a third person novel, the camera describes the scene from above or from afar using neutral and non-opinionated language. This is the part where the narrator describes the rain pouring down on the town, for example.
  • Next, the camera moves in closer and focuses on the characters at the center of the scene, and on the viewpoint character in particular. At this point, the viewpoint character is still being seen from the outside and the language remains neutral and non-opinionated.
  • Finally, the camera moves behind the viewpoint character’s eyes and remains there. The language begins to sound more and more like the viewpoint character’s own first person speaking voice, except it remains in the third person.

At the beginning of a scene, the narration is often called “distant.” That’s because we are not standing in the viewpoint character’s shoes yet. Once we are, the narration becomes “close” – and the longer we spend with the viewpoint character, the closer and more intimate the narration becomes. 

What does this have to do with interior monologue tags? 

When the narration is more distant than close – or when the scene hasn’t “warmed up” yet – you’ll probably want to use a “she thought” tag.
When the narration is close and intimate, and the language is beginning to approximate the viewpoint character’s own speaking voice, tags won’t be necessary. 

In other words, whether or not to use a tag is really a judgment call on your part.
If you believe that using one will help comprehension, use one. If not, don’t.
Just remember that, generally speaking, interior monologue tags will appear during the cooler beginnings of scenes and not after they have warmed up.
The final thing to talk about is how closely interior monologue should match… 

The Character’s Natural Speaking Voice 

In a first person novel, you hear the leading character’s natural speaking voice directly. In third person, you only hear it directly in dialogue or monologue rendered in the first person (as discussed above).
For the rest of the time, you hear the narrator’s voice, which is less subjective, less colorful, less colloquial than the character’s direct voice. 

Like I’ve said, though, the third person narrator’s neutral voice begins to approximate the character’s natural speaking voice when the camera moves behind their eyes, so to speak, and the scene “warms up.” 

During the “cooler” opening section of a scene, any lines of monologue are best written neutrally and factually (and should probably be “tagged,” too). Like here… 

Sometimes men could be so insensitive, she thought. And Frank was in a league of his own. 

Later, once the scene has warmed up, the monologue, while remaining in the third person, can begin to take on the characteristics of the character’s natural first person voice. And you can safely drop the tag, too… 

Jesus! She knew a lot of men opened their mouths without remembering to think first, but Frank had turned insensitivity into a damn art form! 

What About Monologue In a First Person Novel? 

Pretty much everything I’ve said about interior monologue applies to third person novels written in the past tense. (This is by far the most common form of voice and tense used by writers.)
In a third person, present tense novel, it is literally just a case of changing the past tense to present. So instead of writing this… 

Mary closed her eyes and lifted her face to the sun. The summer had been so perfect, she thought. She didn’t want it ever to end.
You write this…
Mary closes her eyes and lifts her face to the sun. The summer has been so perfect, she thinks. She doesn’t want it ever to end. 

Simple. In a first person novel, whether written in the past tense or present tense, interior monologue is easier still. Why? Because it happens naturally, all by itself.
Let me explain that…
The biggest challenge you face in a third person novel is making it clear that the words are indeed the character’s thoughts, and not the narrator’s words. 

That is why, when the viewpoint character is being viewed from a distance, you might use a “thought” tag to make it clear that these words are indeed the character thinking, and only drop using tags once the camera has moved behind the character’s eyes, so to speak. 

But in a first person novel, the camera is always behind the character’s eyes, and so it’s obvious when we hear their direct thoughts. Like here…
I closed my eyes and lifted my face to the sun. The summer had been so perfect. I didn’t want it ever to end. 

There’s nothing to stop you using a tag if you want (“The summer had been so perfect, I thought…”), but it isn’t necessary. It’s obvious that the character is thinking these thoughts in the here and now of the story.
And that’s it – interior monologue in a nutshell (okay, quite a big nutshell!) 

If you’re feeling confused right now, don’t worry about it…
As with all the other theories of fiction, handling interior monologue will become second nature once you’ve taken the “rules” on board, relaxed, and started to apply them to your own fiction without over-thinking them.