clerk

I do the test of adjective / adverb,
question : It is very easy
answer: very is a adverb
I want to know why the answer is adverb

In that example sentence, very is an adverb, easy is an adjective.

Ex: The test is very easy.

Let's check it

a test
=> test is a noun. We know this because nouns take determiners/articles and a is one.

an easy test
=> We know that test is a noun, and that nouns are modified by adjectives, which makes easy and adjective.

a very easy test
=> We know that easy is an adjective, and that adjectives are modified by adverbs, which makes very an adverb.

[+ adjective/adverb]
used to emphasize an adjective, adverb, or phrase:

It feels very cold today.

Here very is adverb, it emphasizes the adjective cold.

[only before noun]
used to emphasize that you are talking exactly about one particular thing or person:

He died in this very room.

Here very is used to modify the noun room. So it is an adjective.