The test: if the meaning resists guessing from verb plus particle, treat it as a phrasal verb. If it is transparent, rely on structure instead.
A quick movement test separates many transitive phrasal verbs from prepositional verbs. With a separable phrasal verb, the object can move to either side of the particle, as in turn off the TV and turn the TV off. A prepositional verb like depend on does not allow this, which is why depend your team on fails. One caveat: inseparable phrasal verbs such as look after also fail the movement test, so for those a dictionary is the reliable check.
One type at a time
The test: if the meaning resists guessing from verb plus particle, treat it as a phrasal verb. If it is transparent, rely on structure instead.
Phrasal verbs come in a few basic types. They divide first into intransitive ones, which take no direct object, and transitive ones, which need a direct object. Only the transitive ones split further into separable and inseparable, so an intransitive phrasal verb can never be separable or inseparable.
- Intransitive, no direct object: I woke up at 10:30 AM.
- Transitive, takes a direct object: You need to fill out this form.
- Separable transitive, the object can move or split the verb: turn off the TV or turn the TV off, and a pronoun must split it, as in turn it off.
- Inseparable transitive, the object stays right after the verb: look after your dog, never look your dog after.
The test: if the meaning resists guessing from verb plus particle, treat it as a phrasal verb. If it is transparent, rely on structure instead.
A quick movement test confirms the split. With a separable phrasal verb, the particle can move: turn the TV off works as well as turn off the TV. With a prepositional verb like depend on, it fails: depend your team on is not English. Pronouns must split a separable phrasal verb, so turn it off is right.
Here are the main types, one example each:
- Intransitive: no direct object, so nothing can be split. I woke up at 10:30. Since there is no object to move, wake up can never be separated.
- Transitive separable: takes an object, and the particle can move around it. Turn off the TV / turn the TV off.
- Transitive inseparable: takes an object that always stays after the whole verb. Look after your dog, never look your dog after.
- Transparent verb plus preposition: the second word is a true preposition, not a particle, as in depend on your team.
The movement test alone can mislead, though. Inseparable phrasal verbs like look after fail it too, just as transparent verb-plus-preposition pairs do, so both can look identical to the test. That is the one place to check a dictionary before deciding.