1.1 To be

Les formes del present de to be (infinitiu) són:

Affirmative
Complete		Contraction		Catalan
I am		I'm		sóc
you are		you're		ets, vostè és
he is		he's		(ell) és
she is		she's		(ella) és
it is		it's		(això) és
we are		we're		som
you are		you're		sou, vostès són
they are		they're		(ell(e)s) són

Negative
Complete		Contraction		Catalan
I am not		I'm not		no sóc
you are not		you aren't, you're not		no ets, no és vostè
he is not		he isn't, he's not		no és (ell)
she is not		she isn't, she's not		no és (ella)
it is not		it isn't, it's not		no és (això)
we are not		we aren't, we're not		no som
you are not		you aren't, you're not		no sou, no són vostès
they are not		they aren't, they're not		no són (ell(e)s)

Negative question
Complete		Contraction		Catalan
am I not?		aren't I?		no sóc?
are you not?		aren't you?		no ets?, no és vostè?
is he not?		isn't he?		no és (ell)?
is she not?		isn't she?		no és (ella)?
is it not?		isn't it?		no és (això)?
are we not?		aren't we?		no som?
are you not?		aren't you?		no sou, no són vostès?
are they not?		aren't they?		no són (ell(e)s)?

Les formes del passat de to be són:

Affirmative		Question		Negative		Negative contraction		Catalan
I was		was I?		I was not		I wasn't		(jo) era
you were		were you?		you were not		you weren't		eres, (vostè) era
he was		was he?		he was not		he wasn't		(ell) era
she was		was she?		she was not		she wasn't		(ella) era
it was		was it?		it was not		it wasn't		(això) era
we were		were we?		we were not		we weren't		érem
you were		were you?		you were not		you weren't		éreu, (vostès) eren
they were		were they?		they were not		they weren't		(ells) eren

To be funciona com a:

1. Verb auxiliar per formar el present continuous, past continuous, etc.;
2. Verb principal.

Com a verb principal, to be correspon tant a ‘ser’ com a ‘estar’, p. ex.:

I am Catalan. (Sóc català/ana.)

It is wrong. (Està malament.)

També hi ha una sèrie d'expressions freqüents que es formen amb el verb to be que en català es tradueixen pel verb ‘tenir’:to be cold/hot/hungry/thirsty/ right/wrong, p. ex.:

I was cold/hot. Error: I have cold/hot. (Tenia fred/calor.)

Peter is hungry/thirsty. Error: Peter has hungry/thirsty. (En Peter té gana/set.)

You are right/wrong. Error: You have right/wrong. (Tens raó/No tens raó.)

Se segueix aquesta mateixa estructura quan es vol expressar l'edat:

Laura is 23 (years old). Error: Laura has 23 (years old). (La Laura té 23 anys.)

Normalment no es fa servir l'auxiliar to do amb to be. Tanmateix, l'imperatiu negatiu es forma amb don't, p. ex.:

Don't be silly! (No siguis poca-solta.)