Missing Auxiliaries - Common Errors in English

Not every language uses auxiliary verbs like English. Languages that don't use auxiliary verbs, replace them with suffixes added onto the ends of verbs. Missing auxiliaries are a common mistake for non-native English speakers, since many languages either omit auxiliary verbs, or have different usage characteristics.

An auxiliary verb is “a highly irregular verb that is used with other verbs to form voice, tense, and mood.” These verbs are also know as “helper verbs”, because of their role in adding meaning to the main verb of a sentence.

Complete list of English auxiliary verbs:

am, is, are, shall, should, be, being, been, was, were, will, would, has, have, had, do, does, did, can, could, may, might, must, ought

Auxiliary verbs have a few grammatical functions:

• Support: Auxiliaries help/change the meaning of a main verb
  i.e. The doctor went home. The doctor is going home.
• Interrogative: Auxiliaries invert to form questions
  i.e. You can go. Can you go?
• Negation: To negate a sentence, not or n’t is added after an auxiliary
  i.e. Charles goes to class. Charles does not go to class.

Depending on the context, some auxiliaries can function alone as the only verb in a sentence; others will not be found without a main verb.

These are known as modal verbs (can, could, may, might, ought, shall, should, will, would, and must).

Modal verbs NEVER appear alone; they always accompany a main verb.