







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 | |
|---|---|
| You know, the landlords should give you some kitchen utensils. | Sabe, os senhorios deviam lhe dar alguns utensílios de cozinha. |
| The train leaves in a few minutes, we should get on soon. | O trem parte dentro de poucos minutos, temos de entrar em breve. |
| Of course, but I can only peel the potatoes with a peeler. | Claro, mas eu só descasco batatas com descascador. |
| Oh, so I should keep my expectations low for tonight, then! | Oh, então devo manter minhas expetativas em baixo para esta noite! |
| My sixth sense tells me I must clean it. | Meu sexto sentido me diz que eu devo lavá-la. |
| You could have brought the book directly! | Podia ter trazido o livro! |
| Umm, I guess it must be in zone-2... | Hum, acho que é na zona 2... |
| I see, but shouldn't they have given you at least a month's notice? | Entendo, mas eles não deveriam ter avisado com, pelo menos, um mês de antecedência? |
| As far as I know, you can only order the things on the menu. | Tanto quanto sei, você só pode pedir as coisas que estão no menu. |
| Maybe you can try some prawn crackers. | Pode experimentar as chips de camarão. |
| Great! Can I have your number, then? | Ótimo! Posso ficar com seu número, então? |
| No, you have to bring your own or buy new ones, dear. | Não, você terá de trazer os seus ou comprar novos, querida. |
| I could only find some eggs, some undated bacon and some olives. | Encontrei alguns ovos, um pouco de bacon sem data e azeitonas. |
| You know I work from home, so I can easily take care of them both. | Você sabe que eu trabalho a partir de casa, por isso posso tomar conta dos dois facilmente. |
| How can you be so sure? | Como você pode estar tão certo? |
| Hm, I would like to see her, but I don't think we should disturb her. | Hum, eu gostaria de a ver, mas eu não quero incomodar. |
| I guess I can leave around four-ish. | Julgo poder sair pelas quatro. |
| Can't we have the meeting without the f*cking IT manager! | Não podemos fazer a reunião sem a m*rda do gerente de TI?! |
| I don't think electric stoves can make the pan burn! | Eu julgo que os fogões elétricos não são capazes de queimar a frigideira! |
| But I have to do it sometimes to visit my family. | Mas tenho de as fazer de vez em quando, para visitar minha família. |