1. A verb is a word which shows action: eat, read, drive, think
or state of being:
2. A verb shows time (tenses): past, present, or future time.
Example: Ridzuan was here.
3. A word that does not show time is not the main verb of the sentence. Look at the following sentence. Which word is the main verb in the following sentence?
The barking dog jumped on the woman.
4. Try changing the sentence to future tense. Which word would you change? The word that changes to future tense is the main verb of the sentence.
It isn't a sentence because bark is not the verb of the sentence. The word barking in the original sentence is functioning as an adjective and is modifying the noun dog. The verb in the original sentence is jumped. The tense of the verb jumped can be changed.
The barking dog will jump on the woman. [future tense]