phrasal verbs

Depending on the meaning of the phrasal verb, it can be used in various situations.  Phrasal verbs often replace regular verbs.

I'll take up fishing as a new hobby.

=

I'll start fishing as a new hobby.

 Phrasal verbs are best learned in context and through repetition.  I try to find texts that use phrasal verbs and have students locate them and try to understand meaning based on context.  Then, I spend various lessons using the verbs in speaking and writing to reinforce the new vocabulary.

You can learn them via rote memorisation, but it is much less fun and some would argue less effective.