An auxiliary verb is a grammatical verb that combines with a lexical verb to express grammatical categories such as tense, aspect, mood, modality, voice, agreement, and polarity ^[1][2]. It typically contributes grammatical rather than primary lexical meaning and forms part of a larger verb phrase or auxiliary verb construction. Auxiliary verbs generally occur with a main verb, which may appear in a non-finite or participial form, although their morphological and syntactic properties vary across languages ^[1][3]. In English, the principal auxiliary verbs include be, have, and do, together with modal auxiliaries such as can, may, must, and will ^[1][2].