Prepositions...

indicate some relationship between a noun and some other element in the sentence and are used with:

- noun phrase or pronoun (most commonly)

e.g.: She fell asleep during the film. ; He went shopping with her.

- adverb phrase

e.g.: Until quite recently, no one knew who she was.

-a verb in the -ing form

e.g.: Thank you for cooking.

- a prepositional phrase or a wh-clause

e.g.: Can you wait until after my appointment? ; I don't like looking at what's infront of me.