What a phrasal verb is
A phrasal verb is a verb plus a particle — a small word such as up, off, on, out, in, down, over or away — where the combination has a meaning of its own.
'Look' means to direct your eyes. 'Look after' means to care for. 'Look up' means to find information. 'Look into' means to investigate. The verb has not changed; the particle has done all the work.
I gave up sugar in January.
Gave up — stopped doing something.
We put the meeting off until Friday.
Put off — postponed.
She gets on well with her host family.
Get on with — have a good relationship.