Deny and refuse

Incorrect: He denied my offer of help.
Correct: He refused my offer of help.

Incorrect: He refused taking the money.
Correct: He denied taking the money.

To deny is to say that something is not true. To refuse is not to take what is offered or not to do what one is asked to do.

Explain me and explain to me

Incorrect: Please explain me this problem.
Correct: Please explain this problem to me.

Fairly and rather

Incorrect: Please close the window. It is fairly cold.
Correct: Please close the window. It is rather cold.

Fairly and rather both mean ‘somewhat’. Fairly is used to express a desirable or pleasant idea.

The car is fairly big. It should be able to seat 8 people.

Rather is used to express an undesirable or unpleasant idea.

The car is rather big. I don’t think I will be able to drive it.

Far and a long way

Incorrect: The station is far from here.
Correct: The station is a long way from here.

Incorrect: The hostel is not a long way from here.
Correct: The hostel is not far from here.

Far is common in questions and negative sentences. In affirmative sentences we use a long way.

Far can be used in affirmative clauses with too, enough, as and so.

Far can also be used to modify comparatives, superlatives and too.

He is by far the best player in the team.
She is far older than her husband.