Phrasal verbs change meaning completely when a preposition is added. They must be learned as fixed phrases.
get on (with)
have a good relationship with someone
get off
leave a bus, train or plane
get along
have a friendly relationship (= get on)
get through
complete a difficult task / pass an exam / reach someone by phone
get over
recover from an illness, shock or disappointment
get away
escape / go on holiday