two-part verbs 2: prepositional verbs

verb + preposition: listen to; look at
Many English verbs are regularly followed by prepositions before objects.
You never listen to me. (NOT You never listen me.)
Alan walked down the road without looking at anybody.
Prepositions are not used when there is no object.
Listen! (NOT Listen to!)
idiomatic meanings: look after, get over
The meaning of a two-word verb can be very different from the meanings of the two parts taken separately.
Could you look after the kids while I’m out? (Look after is not the same as look + after.)
It took him six months to get over his illness. (Get over is not the same as get + over.)
word order: What are you thinking about?
When an object comes at the beginning of a clause (e.g. in a question or relative clause), a two-word verb usually stays together, so that a preposition can be separated from its object and go at the end of the clause. For details of this and other preposition-final structures, see prepositions 5: at the ends of clauses.
What are you thinking about? (NOT About what are you thinking?)
I’ve found the book which I was looking for. (More natural in an informal style than … the book for which I was looking.)
For the difference between prepositions and adverb particles, see adverb particles.
For prepositional verbs in the passive, see passives 5: verbs with prepositions.