Final answer:
The phrase 'for such a young child' in the sentence 'She speaks very distinctly for such a young child' is a prepositional phrase, as it begins with the preposition 'for' and provides additional information about the manner in which she speaks.
Step-by-step explanation:
In the sentence 'She speaks very distinctly for such a young child', the phrase 'for such a young child' is a prepositional phrase. A prepositional phrase usually starts with a preposition (in this case, 'for') and ends with a noun or pronoun (here, 'child'). It functions within a sentence to modify a noun, verb, adjective, or adverb. Prepositional phrases can provide additional information about time, location, manner, cause, and more.
Regarding the options provided:
A. Prepositional phrase: Correct, as described above.
B. Appositive phrase: Incorrect, an appositive phrase renames or provides more information about a noun.
C. Participial phrase: Incorrect, participle phrases begin with a present or past participle and act as adjectives.
D. Gerund phrase: Incorrect, a gerund phrase would start with a gerund (a verb ending in -ing that functions as a noun).
E. Infinitive phrase: Incorrect, an infinitive phrase starts with the word 'to' followed by the base form of a verb.