La estructura básica del verbo "to be":

Afirmativo

SUJETO

VERBO

OBJETO / COMPLEMENTO

(CON Y SIN CONTRACCIÓN)

I

am

a student.

Soy alumno.

You

are

happy.

Eres feliz.

He

is

John.

Es John.

She

is

in the car.

Está en el coche.

It

is

a hot day.

Es un día caluroso.

We

are

David's parents.

Somos los padres de David.

You

are

from Madrid.

Sois de Madrid.

They

are

ours.

Son nuestros.

Negativo

SUJETO

VERBO

OBJETO / COMPLEMENTO

(CON Y SIN CONTRACCIÓN)

I

am not

a student.

No soy alumno.

You

are not

happy.

No eres feliz.

He

is not

John.

No es John.

She

is not

in the car.

No está en el coche.

It

is not

a hot day.

No es un día caluroso.

We

are not

David's parents.

No somos los padres de David.

You

are not

from Madrid.

No sois de Madrid.

They

are not

ours.

No son nuestros.

Interrogativo

VERBO

SUJETO

OBJETO / COMPLEMENTO

Am

I

a student?

¿Soy alumno?

Are

you

happy?

¿Eres feliz?

Is

he

John?

¿Es John?

Is

she

in the car?

¿Está en el coche?

Is

it

a hot day?

¿Es un día caluroso?

Are

we

David's parents?

¿Somos los padres de David?

Are

you

from Madrid?

¿Sois de Madrid?

Are

they

ours?

¿Son nuestros?

Respuestas cortas del verbo "to be"

	Af.					Neg.	(con y sin contracción)
	Yes,	I am.				No,	I am not. (I'm not.)
	Yes,	you are.				No,	you are not (you aren't - you're not)
	Yes,	he is.				No,	he is not (he isn't - he's not)
	Yes,	she is.				No,	she is not (she isn't - she's not)
	Yes,	it is.				No,	it is not (it isn't - it's not)
	Yes,	we are.				No,	we are not (we aren't - we're not)
	Yes,	you are.				No,	you are not (you aren't - you're not)
	Yes,	they are.				No,	they are not (they aren't. - they're not)