Grammar: Groups & phrases: Verb group: Structure of the verb group

Phrasal verbs

Verb + preposition

Many phrasal verbs are formed with prepositions such as against, among, as, at, beside, for, from, into, like, of, onto, upon, with:

Miss Lee looked into the problem immediately. [investigated]
Mrs Gong brought up three children. [raised]

Other prepositions used to form phrasal verbs may also function as adverbs of space or location (sometimes called 'prepositional adverbs'): about, above, across, after, along, around, by, down, in, off, on, out, over, past, round, through, under, up etc:

Kitty put away the dishes after dinner. [stored in their proper place]

Phrasal verbs comprising verb + preposition require a noun group as a second Participant:

By contrast, phrasal verbs comprising verb + adverb, eg Dotty passed out (fainted), have no such requirement. However, it could be argued that the particle up in Inspector Fu looked up his friends in Macau functions as an adverb, and that therefore adverbs may also have a second Participant. 

Much more important that any distinction between adverb and preposition is that we distinguish between two seemingly similar constructions of verb + preposition, one of which is a phrasal verb but the other is not:

The type of verb in Ricky looked at the pictures is sometimes called 'prepositional verb' to distinguish it from a phrasal verb. In a construction with a prepositional verb, the preposition is part of the prepositional phrase and not part of the phrasal verb. 

We distinguish these two types of construction because in a clause with a prepositional verb the preposition cannot be moved to a position following the noun group:

Granny Gong called on her friends. ['visited'] 
Granny Gong called her friends on. 

The inability to move the preposition to a position that separates it from the verb also applies if the noun group is expressed by a pronoun rather than a noun:

Granny Gong called on them. 
Granny Gong called them on. 

The situation is exactly the same if the meaning of call on is 'ask', eg She called on her friends for help. In other words, although the preposition is clearly associated with the verb in terms of its meaning, which makes the verb look like a phrasal verb, the verb group behaves differently from a phrasal verb. 

By contrast, in a clause with a phrasal verb, the preposition can be moved to a position following the noun group. 

Miss Lee turned off the lights. ['deactivated']
Miss Lee turned the lights off.

When the noun group is expressed by a pronoun, it is always moved to final position:

Miss Lee turned them off.
Miss Lee turned off them.  

For more information on prepositional phrases, see Grammar: Groups & phrases: Prepositional phrases: Overview

Note that the term Participant is written with a capital to remind us that it is a functional term.