Modals – NEED, MUST, HAVE GOT TO

[Humble]

Please,
1.What is correct here
He needn’t do that, …? – Yes, he … .The key in my book gives – must he?- Yes, he must. Is it the only possible variant?
2. Is it possible to use have got to in the interrogative and negative?
Have you got to do it right now?
You haven’t got to do it right now.
3. Any difference here?
a)You’ve got to hide your love away.
b)You have to hide your love away
c)You must hide your love away.
Tnx.

[DavyBCN]

Please,
1.What is correct here
He needn’t do that, …? – Yes, he … .The key in my book gives – must he?- Yes, he must. Is it the only possible variant?
2. Is it possible to use have got to in the interrogative and negative?
Have you got to do it right now?
You haven’t got to do it right now.
3. Any difference here?
a)You’ve got to hide your love away.
b)You have to hide your love away
c)You must hide your love away.
Tnx.

1. Should be "need he?" as you should use the same modal verb in the question tag. Must is not the only possible varian as it depends on how strongly the person replying wants to be. You could use the appropriate tense of has to/should, etc.

2. Yes.

3. Not really - they are all giving strong advice.