English phrasal verbs come in many shapes and sizes.
Typically, they’re a verb and preposition combination which, when combined, changes the meaning of the main verb into something else.
Most students of English find them difficult because sometimes the idiomatic uses either make no sense at all, or the meaning change is so drastic that even a good guesser has no idea what they mean.
Sometimes we call them two part verbs, three part verbs, or multi-word verbs.
Whatever you call them, you should know some basic truths regarding phrasal verb usage.
advanced-english-grammar.com is a good place to start to improve your knowledge of English Phrasal Verbs. Use the menu on the left of the website to explore various aspects of Phrasal Verbs.