







In English we use should / shouldn't /ought to / oughtn't to give advice. We use should / ought to to say something is a good thing to do and shouldn't / oughtn't to say something is a bad thing to do.
Example sentences :
Note : To ask for advice we can say: What should I do?
In English, "can" is a modal verb and only has a present, past and conditional form. It can also be used with a future meaning.
Example sentences :
Note : Can is not used to talk about specific possibilities.
Example sentences :
In English, could is used to talk about past ability/ permission/ possibility.
Example sentences :
"Be able to" can be used in the present, past, future, present perfect and as a gerund or infinitive.
Example sentences :
Note : be able to in the present and past is more formal than can or could.
In English we use might or may to say something in the future is possible, but not decided.
Example sentences :
To make questions with might we usually use Do you think...?
Example questions :
In English we can also use might in short answers.
Example short answers :
In English we use have to + infinitive to say something is necessary or obligatory. We normally use have to for a general obligation from an outside source, such as work or the law.
Examples sentences :
In English we use don't have to + infinitive to say something is not necessary or obligatory. It means you can if you want to, but it's not necessary.
Example sentences :
To make questions we use do/does.
Example questions :
Form : ( Must + infinitive without to )
In English we use must + infinitive to talk about rules and obligations. We normally use must when the speaker imposes the obligation, such as a teacher to students, or even to yourself.
Form : ( Mustn't + infinitive without to )
In English we use mustn't + infinitive to say something is prohibited.
Example sentences :
Note : You can often use can't or be + not allowed to instead of mustn't.
Example sentences :
Note : Mustn't and don't have to have completely different meanings.
Mustn't Vs Don't Have To
Note : Have to is a normal verb and exists in all tenses whereas must is a modal verb and its only forms are must and mustn't.
You can also use have to and must for strong recommendations.
Example sentences :
In English we use must when we are sure something is true.
Example sentences :
In English we use may or might when we think something is possibly true.
Examples sentences :
In English we use can't when we are sure something is impossible.
Examples sentences :
Note : In this context, the opposite of must is can't, NOT mustn't!
In the past, can't, could, may, might and must for probability change to can't have, could have, may have, might have and must have + past participle (Verb 3).
In the past, should and ought to change to should have and ought to have + past participle (Verb 3).
Note : the form of "must" for obligation and "can" are exceptions.
Must for obligation changes to had to + infinitive
Can changes to could or was able to
| Modal example sentences | |
|---|---|
| Can he walk properly now? | ¿Puede caminar bien ya? |
| It's a very long time, who could stand it? | Es mucho tiempo, ¿quién podría soportarlo? |
| I don't want to upset you, but I have to tell you something! | No quiero que te enojes, ¡pero tengo que decirte algo! |
| Great! Can I have your number, then? | ¡Estupendo! ¿Me puedes dar tu número entonces? |
| And I can hold Bear, we can let them sniff each other first. | Y yo puedo aguantar a Bear, podemos dejar que se huelan uno al otro primero. |
| Hmm, well, I guess I have to think about it. | Hmm, bueno, supongo que tengo que pensarlo. |
| Same, I can take you out for dinner! | Lo mismo, ¡yo te llevo a cenar! |
| Another big problem is, I can't take Pogo with me. | Otro gran problema es que no puedo llevar a Pogo conmigo. |
| I don't think they can legally be married! | ¡No creo que ellos puedan casarse legalmente! |
| So you can enjoy your meal till I come. | Para que puedas disfrutar de tu comida mientras regreso. |
| Yes, it should be hidden somewhere in the top drawer. | Sí, debe estar escondido en alguna parte del cajón superior. |
| Then we might not be able to find it here, either. | Entonces puede que tampoco podamos encontrarlo aquí. |
| Sure, the room is empty so you can move in whenever you like. | Claro, la habitación está vacía así que puedes mudarte cuando quieras. |
| Okay, we can put all my winter clothes away, then. | De acuerdo, podemos poner en otro lado mi ropa de invierno. |
| Maybe we should start looking for houses in the suburbs first. | Tal vez deberíamos empezar a buscar casas en los suburbios. |
| But we have to leave now. | Pero tenemos que irnos ya. |
| You must work very hard. | Debes trabajar muy duro. |
| Um, I'm going to finish at 5, we can meet at 17:30 if you like. | Um, yo termino a las 5, podríamos reunirnos a las 17:50 si te parece. |
| You should feel very lucky having him as a friend. | Debes sentirte muy afortunado de tenerlo como amigo. |
| When can I pick up my money?! | ¡¿Cuándo puedo recoger mi dinero?! |