Rock and roll will never die. Advertisers promise consumers the world. A phrase is a group of words that lacks either a subject or a predicate or both. Phrases function in useful ways to add information to a sentence or shape it effectively. The new law will restrict smoking in most public places.
Additional information is provided by the prepositional phrase, in most public places.
The prepositional phrase functions here as an adverb, telling where smoking will be restricted. Noun Phrases Made up of a noun and all its modifiers, a noun phrase can function in a sentence as a subject, object, or complement. A tuna sandwich is a popular lunch.