Words such as in, over and with are prepositions. We commonly use prepositions to show a relationship in space or time or a logical relationship between two or more people, places or things. Prepositions are most commonly followed by a noun phrase, a pronoun or the -ing form of a verb.
A particle is a word, normally an adverb, added to a verb to form a phrasal verb:
He looked up.
The plane took off.
Click on a topic to learn more about prepositions and particles.