Fill in the blanks with the most appropriate words.
A- When _____ it _____ raining?
B- Yesterday.
A verb is used to express an occurrence, action, or state. It is the grammatical centre of the predicate in a sentence.
An auxiliary verb is a verb which gives is used in the formation of tenses, moods, tones, etc.
Option D is correct as the reply (yesterday) indicates that we are talking about the past. therefore, simple past tense must be used in the given question.
The other options are wrong as the main verb must be in its first form (start) because simple past tense can only be used.
The correct answer is D) did/start