She is the most intelligent girl of the class. There is no doubt about it.

Hi expert teachers and English lovers,

I have synthesized the following sentences. Please find out mistakes.

(1) She is the most intelligent girl of the class. There is no doubt about it.
She is undoubtedly the most intelligent girl of the class.

(2) He is a good boy. This is certain.
He is certainly a good boy.

(3) The train is very late. This is usual.
The train is usually very late.
The train is very late, which was usual.
The train is very late as usual.

(4) He will come back. He will not be long.
He will come back and won’t be long. I am not satisfied with this.

Many thanks.

(1) should be ‘in the class’ not ‘of the class’, but this applies to the first sentences as well as to the answer.

  1. use options 1 or 3, not the middle option, where you have mismatched tenses.

  2. He will come back before long.

Thank you, BN.

That’s my mistake. Is it correct if I say “which is usual”?

Yes, ‘is’ is correct.

It’s correct in terms of tenses, but doesn’t sound natural unless further explanation is given.
The train is very late, which is usual nowadays.