G1. The Prepositional Phrase is made up of a Preposition and a Noun Phrase.
G2. as adverbials of time and place (e.g. We will be back in a few days.)
G3. as a modifier in a noun phrase (e.g. Helen is the girl in the red dress.)
G4. to show who did something (e.g. The lion was killed by the hunter.)
G5. with double object verbs like give and get (e.g. We gave five pounds to the woman on the corner.)
G6. after certain verbs, nouns and adjectives (e.g. The book belongs to me.)