The first sentence in each set contains a two-part verb ( to have and a past participle). The second sentence contains a fixed-form helping verb and a blank. Select the correct form of the main verb for the second sentence. Ellen and her dance partner have practiced flips for hours.
Ellen and her dance partner could ___________________ flips for hours.
A) practice
B) practices
C) practiced

Question

Quizplus · Accepted Answer

The correct form of the main verb to use with "could" (a modal auxiliary verb) is the base form of the verb, which is "practice." Modal auxiliary verbs like "could" are always followed by the base form of the main verb.

The First Sentence in Each Set Contains a Two-Part Verb