A phrasal verb consists of a verb and a preposition or adverb that modifies or changes the meaning; 'give up' is a phrasal verb that means 'stop doing' something, which is very different from 'give'. The word or words that modify a verb in this manner can also go under the name particle. Phrasal verbs are widely used in both written and spoken English.
Phrasal verbs can be divided into different groups:
Intransitive verbs: These don't take an object.
They had an argument, but they've made up now.
Inseparable verbs: The object must come after the particle.
They are looking after their grandchildren.
Separable verbs: With some separable verbs, the object must come between the verb and the particle.
The quality of their work sets them apart from their rivals.
With some separable verbs, the object can before or after the particle, though when a pronoun is used it comes before the particle.
Turn the TV off.Turn off the TV.Turn it off.
Main source: Usingenglish.com