Prepositions before question words
Prepositions are dropped before common question words. This usually happens after
common verbs like tell, ask, depend, sure, idea and look. This is especially common in
indirect questions.
Tell me about your plans. (Here we use the preposition about before the noun ‘your plans’.)
Tell me what you intend to do. (More natural than ‘Tell me about what you intend to do’.)
(Here the preposition is dropped before the question word what.)
I asked her about her relationship status.
I asked her whether she was in a relationship. (NOT I asked her about whether she was in a
relationship.)
She may win the prize – it depends on her performance.
She may win the prize – it depends (on) how well she performs.
Look at this.
Look (at) what I have brought for you.
The prepositions cannot normally be left out after other verbs.
I am worried about her health.
I am worried about how she is going to cope. (NOT I am worried how she is going to cope.)
Compare:
The teacher asked me what I had done. (More natural than ‘The teacher asked me about
what I had done’.)
The police questioned me about what I had seen. (NOT The police questioned me what I had
seen.)
Your chances of getting a good job can vary according to whether you live in a city or in a
village.
Note that we cannot put if after a preposition. We use whether instead.
I am worried about whether she is happy. (NOT I am worried about if she is happy.)