is this a action verb or linking verb Dogs are very good smellers

I think "grammer" meant dogs are very good spellers ...

No!

Action verbs tell what the subject is DOING.
Linking verbs don't.

www.chompchomp.com/terms/verb.htm

So are you saying that's a typo?

This sentence contains a linking verb. To determine whether a verb is linking or action, you can follow these steps:

1. Find the main verb: In this case, the main verb is "are."

2. Determine if the main verb expresses action or a state of being: In this case, "are" is a form of the verb "to be," which is a linking verb indicating a state of being.

3. Look for a subject complement: A linking verb connects the subject of a sentence to a subject complement. In this sentence, "good smellers" is the subject complement that describes the subject "Dogs."

Therefore, "are" is a linking verb in this sentence.

It's an action verb.