What's a verb?
The important thing to remember is that every subject in a sentence must have a verb. Otherwise, you will have written a fragment, a major writing error.
If you're unsure whether a sentence contains a verb or an action verb, look at every word in the sentence and ask yourself, can a person or thing do this?
What's an action verb?
Example- Potato chips crunch too loudly to eat during an exam.
Crunch is something that we can do, We can crunch popcorn during a movie, we can crunch numbers in math class, Crunch is what the potato chips do, so we call that a verb.
What's a linking verb?
Linking verbs do not express action. They link the subject of the sentence to a word or phrase in the predicate that renames or describes the subject.
Example- Kelly is a shopaholic.
Ising isn't something that Kelly can do, is connects the subject, Kelly, to additional, that she will have a huge credit card bill to pay.
What's an auxiliary verb?
Auxiliary verbs are sometimes called helping verbs because, they are needed to form many of the tenses.
Example- I am standing.
The auxiliary verb am will come only with I.
note that you can't am, this reminds you that they are not action verbs.
Be, have, and do, are the most common auxiliary verbs. Other common auxiliary verbs are could, can, should, would, may, and might.