A phrase refers to a group of words that function together as a unit within a sentence. It is a basic component of language and is used to convey meaning or provide additional information. Phrases can serve different grammatical roles and perform various functions in sentences.

Key aspects of phrases include:

* Structure: A phrase consists of one or more words that work together to convey meaning. It does not contain both a subject and a predicate like a complete sentence does. Phrases can be made up of different word types, such as nouns, verbs, adjectives, adverbs, prepositions, or conjunctions.

* Types of phrases: There are various types of phrases, including noun phrases, verb phrases, adjective phrases, adverb phrases, prepositional phrases, and conjunctional phrases. Each type has its own specific function and structure within a sentence.

* Functions: Phrases perform different functions within sentences. For example, noun phrases can function as subjects, objects, or modifiers. Verb phrases can function as predicates, expressing actions or states. Adjective phrases and adverb phrases provide additional information about nouns and verbs, respectively. Prepositional phrases indicate relationships between other words, and conjunctional phrases connect words, phrases, or clauses.

* Modifiers: Phrases can function as modifiers, adding descriptive or explanatory information to other words or phrases in a sentence. These modifiers can provide details about time, place, manner, or other aspects.

* Importance in sentence structure: Phrases play a crucial role in the structure and coherence of sentences. They provide additional information, clarify meaning, or give context to the main ideas expressed in the sentence.

Understanding phrases and their functions is essential for effective communication and comprehension of written and spoken language. Mastery of phrases contributes to constructing well-formed and meaningful sentences.