A verb is a word in a sentence that is performing the action in the sentence.

Example:

He likes tea.

In the above example, likes is the verb as it is referring to the action taking place which is like or liking of tea.

A verb has various forms and today I will be discussing about copular verb.

Copular Verb:

A verb is termed as a copular verb if it joins together the adjective or noun complement to the subject of the sentence.

Example:

Seem, sound, appear, be, become etc.

When a subject and its compliment represent the same thing in a sentence, the verb used is termed as copular verb.

Sam is my best friend.

In the above example, is is the copular verb and it asserts that Sam and my best friend represent the same person.

Anna is American.

The above sentence is also an example of copular verb and is in the above example show the American-nes of Anna or the quality of being American to Anna.