auxiliary verb verb used with notional verbs to show tense, voice, or emphatic mood, and to form a question or negative statement, 大 meaningless itself 大 cant be used as v aloneauxiliary verb verb used with notional verbs to show tense, voice, or emphatic mood, and to form a question or negative statement; ＊ meaningless itself; ＊ can’t be used as V. alone