Level: beginner

The modal verbs are: 



We use modals to show if we believe something is certain, possible or impossible:

My keys must be in the car.
It might rain tomorrow.
That can't be Peter's coat. It's too small.

We also use them to do things like talk about ability, ask permission, and make requests and offers:

I can't swim.
May I ask a question?
Could I have some tea, please?
Would you like some help?

Modal verbs




Sir, You must have done that. haven't you or mustn't you ?

You might not have done that. have you or might you ?

what Should I use as tag questions ?

Hello SonuKumar,

I'd recommend 'right?' in a case like this. That's what I'd do as a native speaker. I honestly don't know what the correct verbal form would be and I haven't been able to find the answer in my reference works, either. Perhaps a form exists, but if so, it would probably sound quite unusual these days. For these reasons, I'd recommend 'right?', which performs the same function as a question tag.

All the best,
The LearnEnglish Team

If I write an academic essay, which modal verb (could or would) will be more suitable to express a possible out come, for example , air pollution would or could be the underlying cause lung cancer.

Hello Annamol,

For that specific sentence, I would recommend 'could' over 'would'. You can read more about both verbs on the pages linked to below.

All the best,
The LearnEnglish Team

Sir, He comes from his work and goes somewhere here so He must live here if we have to rewrite this last sentence so should we write it like this He definitely lives here, He probably lives here or we imagine he lives here ?

Sir, Though I know that we can't use 'Could' for past until we have two occasions, one of which shows past like this (I could run fast when I was a child) But with adverb like 'past and before' Can we use 'Could' like this I can't do it now But I could do it before or in the past or Just simply I could do it before or should we always say I was able to do this ?

Hello SonuKumar,

You can use 'could' to talk about past general ability (like in the sentences you ask about). It's also common to use 'used to' ('I used to be able to do it'), but there's nothing wrong with 'could'.

All the best,
The LearnEnglish Team

can you help me with this:
1. Choose the best answer to complete the following:
1) You will have to carry out the agreed program....... your own personal feelings
a) no matter
b) whatever
c) whatever are
d) however

Hello Casimir,

Could you please tell us what you think is the correct answer? If you can explain why, that will help us help you better.

All the best,
The LearnEnglish Team

Hello Kirk
I think B and C are the best because A requires a pronoun after it and D is totally wrong as there is no verb part in the sentence part.
Thank you for your support