Transitive phrasal verbs require an object, i.e. a person or thing that receives the action of the verb. Here are some examples:
- Our neighbours kindly looked after our dog when we went away on holiday.
- John forgot to switch off the light before he went to bed.
- Can you turn down the music, please? I'm trying to study.
Intransitive phrasal verbs do not require an object. Here are some examples:
- My car broke down on my way to work this morning.
- After almost 5 years together, David and Sarah split up.
- The plane took off as scheduled, at 11:15.
When the verb and the particle can be separated by the object, this is a separable phrasal verb. Separable phrasal verbs are, by definition, transitive only. Here are some examples:
- He came into the room and turned the light on (or 'turned on the light').
- I asked her to pick Peter up at the station (or 'pick up Peter').
- She always looks new words up in the dictionary (or 'looks up new words').
Note that when the phrasal verb is separable, if the object is an object pronoun, the object must separate the verb and the particle. For example:
- Peter asked her to pick him up at the station (not 'pick up him').
Many transitive phrasal verbs can not be separated by the object. These are inseparable phrasal verbs. Here are a few examples:
- He is looking into the possibility of studying abroad next year.
- I came across this old photo when I looking for a book the other day.
- Sally got over her illness very quickly.
Note that two particle phrasal verbs are always inseparable. For example:
- We are all really looking forward to the concert next week. It's going to be great!