Learn Spanish (Latin America): Mientras coqueteaba, me preguntó si me gustaba el ajo. - While he was flirting, he asked me if I liked garlic.

When reporting a past conversation introduced by a preterite verb like preguntó, verbs that were originally in the present tense shift back one step to the imperfect. The direct question "¿Te gusta el ajo?" becomes the reported statement "...si me gustaba el ajo."

Why do we use si to connect the two parts of the sentence?

Just like in English, we use si (if/whether) to report yes/no questions. Because the original question was a simple yes or no, we need si to introduce it. Notice that this si means "if" and doesn't have an accent mark, unlike sí (yes).

Coqueteaba could mean "I was flirting" or "he/she was flirting." How do we know it means "he" here?

Grammatically, it could be either! The imperfect endings for "yo" and "él/ella" are identical (-aba). We rely on the English translation or the broader context of the conversation to know it was "he". If a speaker needs to clarify, they would add the pronoun: mientras él coqueteaba.

Why does the sentence use el ajo instead of just ajo?

With verbs like gustar, the thing that is pleasing is grammatically the subject of the sentence. In Spanish, when you talk about a general category or substance (like garlic in general) as the subject, you must include the definite article.