Whatever level of English you are, you will always find prepositions a complex part of the English grammar. It is true to say that prepositions in TIME and PLACE are pretty straight forward once you have learnt the rules, for instance, the preposition IN for PLACE is simple, just remember that you use it when talking about enclosed places i.e. in my pocket, in my house, in the bottle. Prepositions are small words that link a group of words like nouns, pronouns and phrases to other parts in a sentence. The exercise below is designed for a low intermediate level of English, see how you do.