Hoy os dejamos unos “truquis” para utilizar los modales de obligación “must & have to” y también cómo expresar falta de obligación (lack of obligation) con los modales don’t have to, don’t need to, didn’t need to. Vamos allá!

HAVE TO / MUST

We use these verbs to say that is necessary to do something, but there are some differences:

Have to
The speaker is just giving facts. Or there’s an «outside authority» who tells you to do something.
E.g. I have to complete the report for our client.

We can use “have to” in all verb tenses.

Must
The speaker thinks is necessary, feels is his responsibility to do something.
E.g. I must finish all these paperwork today.

We only use “must” in the present tense, to express obligation in other tenses we use “have to”.
E.g. I had to finish all the paperwork last Friday.
I will have to finish all the paperwork before Friday.

DON’T HAVE TO / MUSTN’T

When used in the negative form, they mean different things:

Don’t have to /don’t need to
It means is NOT necessary that we do something.
E.g. You don’t have to bring anything.
They don’t need to bring anything.

Mustn’t
It means is necessary NOT to do something. (it’s an obligation not to do something).
E.g.He mustn’t talk to us like that.
You mustn’t tell anyone.
We mustn’t be late for the meeting.

DIDN’T NEED TO / DIDN’T HAVE TO DO

We use didn’t need to / didn’t have to meaning that something was not done because it was not necessary.
E.g. We didn’t need to call the technical services, we just fixed it ourselves.
They didn’t need to work until late. We still have time until deadline.
I didn’t have to prepare a cake, but they all appreciated it.

Parece mucho pero en realidad son tres cositas, te las resumimos:

-Must / have to > obligación, sobre todo “have to” que se puede utilizar en cualquier tiempo verbal

-Mustn’t > obligación de NO hacer algo (o prohibición de hacer algo)

-Don’t have to / don’t need to (y sus formas en pasado) > falta de obligación, o lo que es lo mismo, no es necesario hacer algo.

Esperamos que te sirva de ayuda 😉

Cuándo usar will y going to en inglés. Para hablar del futuro en inglés usamos sobre todo will y going to. En realidad es fácil, pero a veces nos liamos porque en algunos casos podemos usar tanto uno como otro, y no hay una gran diferencia de significado. No te preocupes que lo vemos paso por paso y con ejemplos para quede claro.

Will

usamos will cuando tomamos una decisión espontánea

E.g.
I’m not feeling well, I think I’ll go home.
I’m hungry. I’ll buy something to eat.
Are you going for a walk? I’ll go with you.
It’s late. I’ll finish this tomorrow.

también usamos will cuando hacemos una promesa (o nos ofrecemos a hacer algo)

E.g.
I’ll send you an email with the information.
Don’t worry, I’ll help you.
I won’t tell anyone your secret.
We’ll take care of everything.

Will y going to

podemos usar will y going to cuando hablamos de predicciones

E.g.
Look at those clouds. It’s going to rain.
I think it will rain tomorrow.
They will not win the league this season.
They are not going to win the league this season.

En estos casos, no hay una gran diferencia entre usar will o going to, aunque es cierto que usamos going to cuando de alguna manera hay evidencias o hechos que nos hacen pensar que algo ocurrirá. Por ejemplo

E.g.
I’m not feeling well. I think I’m going to catch a cold.
They haven’t played well. They are not going to win the league.