Helping (Auxiliary) Verbs

Helping verbs are verbs that work together with the main verb to give information about verb tense, mood, or voice. They must come before the main verb. If you are unsure, check for another verb (main verb) next to what you think is the helping verb. 

However, be careful because sometimes an adverb may come in between the helping verb and the main verb (e.g. the bird will probably be eating by the usual spot).