0
It was a rotten way to end what had been a rotten day. The fruit was rotten. The word rotten can be used as an adjective or an adverb.
the adverb is rotten :D
An egg that has gone rotten.
Rotten is an adjective.
It depends what you mean......... eg. 'the apple I found is rotten' or 'she is a rotten speller'