Prepositions

Basic prepositions:
Here you can find some exercises on basic prepositions.  The key to the exercises is hereby made available. (Source: English Grammar in Use: Intermediate by Raymond Murphy)

Noun, adjective and verb + preposition:
Here you can find some exercises on nouns, adjectives and verbs which are used with certain prepositions.  The key for the exercises are also hereby made available. (Source: English Grammar in Use: Intermediate by Raymond Murphy)

Phrasal verbs:
Here you can find some exercises on phrasal verbs.  The key to the exercises is hereby made available. (Source: English Grammar in Use: Intermediate by Raymond Murphy)

You can hereby find a link for more online exercises on the topics above.