Is takes an adverb or adjective?

Passed is a verb form or adjective.

But there are two Words that sound exactly alike:

PASSED - adjective meaning went by, accepted, or succeeded

It is the past tense and past participle of the verb "to pass"

PAST - adjective meaning 'former', adverb meaning going by, or in the past

It can also be a preposition (passed cannot be a preposition).

- If it is a verb form, it is always passed. If it comes before a noun, it is passed for something that has passed, and past for a previous moment in time.

- If it comes after a verb, it is past. If it comes after a preposition, it is past.

Examples:

A passed warning sign could result in an accident.

A passed exam is the result of proper study.

His past life no longer interested him.

The car drove past at a high speed.

He did not known how to get past the obstacle.

All of his troubles were in the past.

The time for worrying has passed. (verb)

The time for worrying is past. (past as an adjective)