
Kayleigh N. answered 01/05/23
Master's degree in Curriculum and Instruction with an English emphasis
An adjective clause is a group of words that modify a noun, much the same as an adjective. These clauses typically begin with relative pronouns like who, which, or that. However, the most important function of an adjective clause is to specify, describe, or modify the subject or a noun in some way.
In the first sentence, who eat too much, is the adjective clause because it describes the kind of people that die early. In this example, the adjective clause is headed by a relative pronoun, who.
In the second sentence, however, things are a little trickier. The clause because it was expensive could arguably be considered a functional adjective clause because it works to describe the subject it. However, outside of this specific question, I would not necessarily label that particular dependent clause as an adjective clause.