Unlike nouns, every sentence requires a verb. It's therefore imperative that your students learn to identify a verb as early as possible in grammar classes. Without this basic knowledge, they'll have trouble later picking the right tense and using the correct form. Their essays and exam questions will likely end up being full of sentence fragments. Follow these steps to teach your students to know a verb.

Begin with the most basic kind of verb, one that shows action. This is the easiest for small children to understand. In a sentence like "Jill ran up the hill," it'll be easy for them to know which of these words is the verb.
2

Explain a verb's relation to the subject of the sentence. Start them off on simple sentences where the doer of the action comes right before the verb. Then move on to more complicated examples like "The cat on the mat swishes its tail."
3

Talk about the verb in relation to the object in the sentence. Because the object often comes right after the verb, this may help students who get easily confused about nouns.
4

Emphasize the function of a verb as a way of knowing which of the words in a sentence it is. A word like "walk," which can be both a verb and a noun, confuses children unless they understand that verbs show action while nouns denote a person, place or thing.
5

Teach your students linking verbs once they get the hang of identifying action verbs. Unfortunately there's no way to avoid memorization here, but telling them that linking verbs often accompany action verbs can help them recognize them.
6

Introduce the kids to the verb endings "ed" and "ing" as a way to pick out verbs from other parts of speech. Emphasize, however, that they should look for other signs discussed in these steps to verify that the word is indeed being used as a verb in the sentence.
7

Instruct them on irregular verbs once they've memorized their linking verbs. Though learning to recognize special forms can be frustrating, it's an easy way to know what the verb in the sentence is.

http://grammar.ccc.commnet.edu/grammar/quizzes/verbmaster.htm