What is the definition of a linking verb? First understand as liking verb is a connection of two words, first word is subject and second is informative word of subject. The Linking verb definition is a grammar term for a verb. It connects a subject with a noun or adjective word. It is the subject. For undersand better about linking verb, read this sentence, "They are cold." in this sentence, are is liking verb.
Your next question is What are all of the linking verbs? or What is a linking verb in English grammar?To Be forms are linking verbs, yes you're think in right direction. Linking verbs are the oppose of action verbs, because it don't create any action or movement, but connect subject to the complement of subject.
Some other common linking verbs are used so you must learn these all linking verbs which are common to use in English Grammar.
Students can understand well reading list of linking verb sentences examples here. You know a linking verb is a verb. It joins the subject of a sentence to another noun or phrases. It is sometimes known as a copula or a copular verb. Linking verbs do link to the action verb.
Now you have understood well.