Choose the correct sentences.

1.  ab

a) Is it OK if I arrive half an hour late?

b) Is it OK if I'm arrive half an hour late?

2.  ab

a) What we should do if we get lost?

b) What should we do if we get lost?

3.  ab

a) Do I need to bring a present?

b) Do I need bring a present?

4.  ab

a) Was I did something wrong?

b) Did I do something wrong?

5.  ab

a) Is this a bad time? I come back later.

b) Is this a bad time? I can come back later.

6.  ab

a) If I'm you, I'd apologise.

b) If I were you, I'd apologise.

7.  ab

a) Sorry about that. I didn't know.

b) Sorry for that. I didn't know.

8.  ab

a) My apologise. I didn't realise.

b) My apologies. I didn't realise.

9.  ab

a) No, it's not the necessary.

b) No, it's not necessary.

10.  ab

a) Don't worry. It's fine.

b) You don't worry. It's fine.