The adjective clause in the following sentence modifies ? the time for complaints about the tax notices you have received has already passed.

The time for complaints about the tax notices you have received has already passed.
 It is all about the ‘tax notices’.  

Adjectives are word used to define or modify a noun or pronoun. An adjective phrase or adjectival phrase is a phrase that describes and modifies the noun. It could be used as attributive or predicative. Attributive adjective is included in the in the noun phrase it modifies while predicative adjective is not included in the noun phrase it modifies.   An adjective phrase or adjectival phrase is a phrase that describes and modifies the noun. It could be used as attributive or predicative. Attributive adjective is included in the in the noun phrase it modifies while predicative adjective is not included in the noun phrase it modifies.