What are short forms in English?

Short forms are contractions: two words written as one with an apostrophe for the missing letters. I'm is I am, don't is do not, they've is they have, won't is will not. They are the usual shape of spoken English. Full forms are used for stress, short answers, and formal writing.

When should I avoid contractions?

In academic essays, legal writing, and anywhere a style guide forbids them. Also when the auxiliary is the stressed word: She is the lock-keeper, not the apprentice. And in a short answer that ends the turn: Yes, I am, not Yes, I'm.

What is the difference between it's and its?

It's is a contraction of it is or it has: It's raining. It's been a long shift. Its is the possessive of it, like his or her: The barge lost its visor. If you cannot expand the word to it is or it has, write its.

How do I know whether I'd means I had or I would?

Look at the next word. A past participle means had: I'd seen the chart. A bare verb means would: I'd wait by the cistern. The same test works for he'd, she'd, we'd, and they'd.

Is ain't a short form of am not?

Historically it has been used for am not, is not, are not, has not, and have not in some dialects. It is widely understood, but it is not part of standard written English. The standard forms are I'm not, isn't, aren't, hasn't, and haven't.

English grammar · Beginner

Short Forms in English: Contractions with Apostrophes

Written by Eleanor Whitfield, Lead English Curriculum Editor · Reviewed September 2026

Short forms, or contractions, squeeze a pronoun or a noun together with an auxiliary or a negative: I'm, she's, they've, don't, isn't, won't. The apostrophe marks the missing letters. They are the normal shape of spoken English and of informal writing. Full forms (I am, they have, do not) belong in careful writing and in some stressed replies.

I'm at the tram depot, so I can't meet you at the marina.

I'm shortens I am; can't shortens cannot

What it is

A short form joins two words into one by dropping sounds and marking the gap with an apostrophe. The first word is usually a pronoun or there; the second is be, have, will, would, or not. I'm is I am. Don't is do not. Won't is an irregular spelling of will not. English uses these forms constantly in speech because unstressed auxiliaries shrink. Writing them is a register choice: emails, dialogue, and most web pages use them; academic essays and legal notices often do not.

She's got the docket, but they haven't signed it yet. (She's is she has; haven't is have not.) She is the lock-keeper. (Full form, because is is the main verb being stressed.)

How to spot it

Look for an apostrophe inside a small word that still has a verb job: I'm, you're, he's, it's, we're, they're, I've, we've, I'll, I'd, don't, doesn't, didn't, isn't, aren't, wasn't, haven't, hasn't, hadn't, won't, can't, couldn't, wouldn't, let's. If the apostrophe is marking a missing letter in an auxiliary or in not, it is a short form, not a possessive.

We're waiting by the millrace. (we're = we are)
He doesn't work the night winch. (doesn't = does not)
They'll meet us on the jetty. (they'll = they will)
I'd already checked the cistern. (I'd = I had, because a past participle follows)

I'd can be I had or I would. The next word tells you which: I'd seen (had), I'd go (would). She's can be she is or she has: She's late (is), She's left (has).

Short Forms (Contractions) Quick Reference

The contractions you meet first

Short form	Full form	Typical use
I'm, you're, he's, she's, it's, we're, they're	I am, you are, he is…	be in the present
I've, you've, he's, she's, we've, they've	I have, you have, he has…	have as an auxiliary
I'll, you'll, he'll, we'll, they'll	I will, you will…	future with will
I'd, you'd, he'd, we'd, they'd	I would or I had	depends on the next word
don't, doesn't, didn't	do not, does not, did not	present and past simple negatives
isn't, aren't, wasn't, weren't	is not, are not, was not, were not	be negatives
haven't, hasn't, hadn't	have not, has not, had not	perfect negatives
can't, won't, couldn't, wouldn't, let's	cannot, will not, could not, would not, let us	modals and suggestions

Common Short Forms (Contractions) Examples in English

Short forms cluster by the word they shrink. Each group has one spelling trap:

Be and Have

I'm on the harbour wall.: I am
You're early for the foundry shift.: you are
We've sealed the quarry gate.: we have, auxiliary
There's a barge on the millrace.: there is

There's is the usual spoken form even before a plural in casual speech (There's two crates), but careful English keeps there are.

Negatives

I don't know the lock-keeper.: do not
The winch isn't working.: is not
She hasn't seen the chart.: has not
We can't take the tram after midnight.: cannot, one word in the full form

Am not has no everyday contraction with I except I'm not. Ain't exists in some dialects but is not standard in this register.

Will and Would

I'll wait by the cistern.: I will
She'll sign the docket tomorrow.: she will
We'd rather take the barge.: we would
He wouldn't open the quarry in the rain.: would not

Won't is irregular: it does not look like will. Shan't (shall not) is now rare except in some British speech.

Questions and Replies

Where's the visor?: where is
What's the millrace like at dusk?: what is
Who's working the night winch?: who is
“Are you ready?” “Yes, I am.”: the short form does not take a stressed yes

Short answers that stand alone keep the full auxiliary: Yes, I am. No, she hasn't. Yes, I'm is unfinished.

How Short Forms Work

The apostrophe is a spelling mark for a spoken reduction, with a few fixed exceptions.

The Apostrophe Replaces Missing Letters

In don't, the apostrophe stands for the o of not. In I'm, it stands for the a of am. In she's, it stands for i or ha, depending on whether the full form is is or has. You never add a second apostrophe for the same gap, and you never use an apostrophe to make a plural (visors, not visor's, when you mean more than one visor).

They aren't on the jetty.

are + not, o missing

Apostrophe = letters left out.

Contract Unstressed Auxiliaries, Not Stressed Ones

Short forms attach to a pronoun, there, here, now, or a wh-word when the auxiliary is unstressed. If you are contradicting or emphasising, you keep the full form: She is the lock-keeper, not the apprentice. In writing, a noun phrase can take a contraction (The skipper's waiting), but long noun phrases with a contraction are clumsy.

It's the lock-keeper. It is the lock-keeper, not the apprentice.

unstressed it's; stressed is in the correction

Stress keeps the full form.

Won't, Can't, and Let's Are Irregular

Will not becomes won't, not willn't. Cannot is already one word and becomes can't. Let us becomes let's when you mean a suggestion (Let's check the cistern), but remains let us in a request for permission (Let us through).

Let's check the cistern. We won't stay long.

let's for a suggestion; won't for will not

Learn won't, can't, and let's as whole spellings.

Do Not Contract a Main Verb Have in American English

I've a spare visor is possible in some British speech as a reduction of I have. American English, and most careful British writing, keeps I have a spare visor for possession and uses I've only when have is an auxiliary (I've packed the visor) or when the idiom is have got (I've got a spare visor).

I've packed the visor. I have a spare visor.

I've with a participle; have as a main verb stays full in careful style

I've needs a participle or got after it.

Common Mistakes with Short Forms (Contractions)

Incorrect: The barge lost it's visor.

Correct: The barge lost its visor.

It's means it is or it has. The visor belongs to the barge, so the word you want is the possessive its, which never takes an apostrophe.

Incorrect: Your waiting by the millrace.

Correct: You're waiting by the millrace.

Your is a possessive adjective. The sentence needs you are, which contracts to you're.

Incorrect: Yes, I'm.

Correct: Yes, I am.

A short answer cannot end on a contracted am, are, or is. The auxiliary is stressed, so it stays full.

Incorrect: He don't work the night winch.

Correct: He doesn't work the night winch.

The third-person present negative contracts does not to doesn't, not do not to don't. Don't stays with I, you, we, and they.

Lookalikes: It's, You're, They're, Who's

Four pairs cause almost all apostrophe errors, because one member is a contraction and the other is a possessive or an adverb.

It's and its

It's always means it is or it has. Its (no apostrophe) is the possessive of it, like his.

It's raining on the quarry.: it is
It's been a long shift.: it has
The barge lost its visor.: possessive, no apostrophe

If you can expand the word to it is or it has, write it's. If you cannot, write its.

You're / your, they're / their / there, who's / whose

The contraction always expands to a pronoun plus a verb. The other spellings never do.

You're early. Your docket is here.: you are vs. possessive
They're on the jetty. Their barge is late. Wait there.: they are, possessive, place
Who's on the winch? Whose visor is this?: who is vs. possessive

The expansion test settles every one of these in a second.

Quick Check: Short Forms (Contractions)

Write the short form, or choose the lookalike that fits.

1. We ___ (are) waiting by the millrace.

Answer: We're

we are contracts to we're

2. The winch ___ (is not) working.

Answer: isn't

is not

3. The barge lost ___ visor. (it's / its)

Answer: its

possessive, no apostrophe

4. ___ on the jetty? (Who's / Whose)

Answer: Who's

who is

5. I ___ (will not) stay after midnight.

Answer: won't

irregular short form of will not

Short Forms (Contractions) FAQs

What are short forms in English?: Short forms are contractions: two words written as one with an apostrophe for the missing letters. I'm is I am, don't is do not, they've is they have, won't is will not. They are the usual shape of spoken English. Full forms are used for stress, short answers, and formal writing.
When should I avoid contractions?: In academic essays, legal writing, and anywhere a style guide forbids them. Also when the auxiliary is the stressed word: She is the lock-keeper, not the apprentice. And in a short answer that ends the turn: Yes, I am, not Yes, I'm.
What is the difference between it's and its?: It's is a contraction of it is or it has: It's raining. It's been a long shift. Its is the possessive of it, like his or her: The barge lost its visor. If you cannot expand the word to it is or it has, write its.
How do I know whether I'd means I had or I would?: Look at the next word. A past participle means had: I'd seen the chart. A bare verb means would: I'd wait by the cistern. The same test works for he'd, she'd, we'd, and they'd.
Is ain't a short form of am not?: Historically it has been used for am not, is not, are not, has not, and have not in some dialects. It is widely understood, but it is not part of standard written English. The standard forms are I'm not, isn't, aren't, hasn't, and haven't.