A noun phrase, or nominal (phrase), is a phrase that has a noun (or indefinite pronoun) as its head or performs the same grammatical function as a noun. Noun phrases are very common cross - linguistically, and they may be the most frequently occurring phrase type. Noun phrases often function as verb subjects and objects, as predicative expressions and as the complements of prepositions. Noun phrases can be embedded inside each other; for instance, the noun phrase some of his constituents contains the shorter noun phrase his constituents .