Adverb or Adjective?

[ehsaning]

Hello,
I'm conflicted about recognizing Adverb and Adjectives in the following sentences:

The train went quite fast. >>>> fast is adverb
Sarah is feeling quite tired >>> tired is adjective.

Why tired is adjective? why it is not an adverb?
Why fast is not an adjective?

[Barb_D]

In the first, "fast" describes how the train was MOVING. Moving is a verb, so you use an adverb to describe it.

In the second, "tired" describes SARAH. Sarah is a person, a noun. Adjectives describe nouns.

There are some verbs (is, feels, smells, looks, seems) that describe the thing/person, so you use an adjective.
I feel good.
It smells delicous.
You look beautiful
She seems tired.