







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 shouldn't have woken her up in the morning! | Você não a devia ter acordado de manhã! |
| No way, what else can I have instead of chips? | Não pode, o que eu posso pedir em vez de batatas fritas? |
| I have finished my wine, we can leave any time you want. | Eu já bebi o meu vinho, podemos ir quando você quiser. |
| But I have to do it sometimes to visit my family. | Mas tenho de as fazer de vez em quando, para visitar minha família. |
| We can get return tickets when we come back. | Podemos comprar os bilhetes de regresso quando voltarmos. |
| Mike, can you hear me? | Mike, consegue me ouvir? |
| When can I pick up my money?! | Quando posso pegar meu dinheiro?! |
| Umm, yeah, I think we should consider living in Angel, too. | Hum, sim, eu penso que também devemos considerar viver em Angel. |
| Cate, my queue is going faster, you can come over here. | Cate, minha fila está indo mais rápido, você pode vir para aqui. |
| Of course, but I can only peel the potatoes with a peeler. | Claro, mas eu só descasco batatas com descascador. |
| Alright... Ah! I can see it now! | Muito bem... Ah! Encontrei! |
| Umm... I'm sorry, but I can't find a booking in that name. | Hum... Lamento, mas não encontro nenhuma reserva com esse nome. |
| You know, the landlords should give you some kitchen utensils. | Sabe, os senhorios deviam lhe dar alguns utensílios de cozinha. |
| I can pay 700 or maximum 750 per month, only if I have to! | Eu posso pagar 700 por mês, ou 750, no máximo, mas apenas se tiver de ser! |
| I said it was a mistake, I was terribly sorry, what else could I say? | Eu disse que era engano, que lamentava muito, o que mais poderia dizer? |
| Haven't decided yet, but you can call me when you finish. | Não decidimos ainda, mas você pode me ligar quando sair. |
| Check the cupboard just in front of you, it should be there. | Procure no guarda-loiça na sua frente, deve estar lá. |
| Too bad, they must have understood you are a liar, then. | Azar, eles devem ter percebido que você é uma mentirosa. |
| You must work very hard. | Você deve trabalhar muito. |
| Umm, we can raise it just a little bit, like 50%. | Hum, podemos subir um pouco, como 50%. |