Final answer:
The prepositional phrase in the sentence is "before my practice," which functions as an adverbial phrase modifying the verb "told" by indicating the time of the action.
Step-by-step explanation:
The prepositional phrase in the sentence "My mother told me before my practice?" is "before my practice." This phrase sets a time frame for when the speaker's mother told them something, which fits the definition of a prepositional phrase as it includes the preposition "before" and modifies the verb "told." Prepositional phrases are parts of a sentence that begin with a preposition and end with the object of the preposition, typically a noun or pronoun. They can provide various types of information, such as location, time, reason, or method.
Prepositional phrases often serve as adverbials, modifying verbs, adjectives, or other adverbs, as in the example sentence provided. In our specific case, "before my practice" is an adverbial phrase modifying the verb "told" by specifying the time at which the action took place.