Auxiliary verbs in Bulgarian grammar are used to form various tenses, moods, and aspects in conjunction with the main verbs. They help to express time, possibility, obligation, and necessity in the language. Some of the most common auxiliary verbs in Bulgarian include “съм” (to be), “ще” (will), “бих” (would), “имам” (to have), and “мога” (can). These auxiliary verbs are essential components of the language, and understanding their usage is crucial to mastering Bulgarian grammar.