Sujeito + Verbo (Auxiliar)
 
I am = I'm you are = you're
I have = I've you have = you've
I will = I'll you will = you'll
I would = I'd you would = you'd
I had = I'd you had = you'd

he is

=

he's

she is

=

she's
he has = he's she has = she's
he will = he'll she will = she'll
he would = he'd she would = she'd
he had = he'd she had = she'd

it is

=

it's

we are

=

we're
it has = it's we have = we've
it will = it'll we will = we'll
it would = it'd we would = we'd
it had = it'd we had = we'd

they are

=

they're

there is

=

there's
they have = they've there has = there's
they will = they'll there will = there'll
they would = they'd there would = there'd
they had = they'd there had = there'd

Verbo (Auxiliar) + Negação

am not

=

aren't (1), ain't (2)

may not

=

mayn't (4)
are not = aren't, ain't (2) might not = mightn't
cannot = can't must not = mustn't
could not = couldn't need not = needn't
dare not = daren't (3) ought not = oughtn't
did not = didn't shall not = shan't (3)
do not = don't should not = shouldn't
does not = doesn't used not = usedn't (5)
had not = hadn't was not = wasn't
has not = hasn't, ain't (2) were not = weren't
have not = haven't, ain't (2) will not = won't
is not = isn't, ain't (2) would not = wouldn't

(1) utilizada na interrogativa em inglês britânico
(2) utilizada em inglês americano e não considerada padrão por muitos
(3) raramente utilizada em inglês americano
(4) inglês britânico mas raramente utilizada
(5) inglês britânico mas raramente utilizada; utiliza-se mais a forma didn't use (to) e é somente no passado