What word does the adjective clause modify?

This course deals with facts that everyone should know.

course

deals

facts

everyone

know

Facts

Explanation:

Adjectives are words that modify nouns, noun phrases, and pronouns, providing detail about their qualities or state of being. Adjective clauses are groups of words containing a subject and a predicate (clauses) and providing additional information about the noun, noun phrase, or pronoun. They begin with relative pronouns (e. g. who, whom, whose, that, which) or relative adverbs (when, where, why).

In the given example, the adjective clause is that everyone should know. The word the clause modifies is the noun facts: facts that everyone should know, providing additional information about it (the sentence This course deals with facts is also correct, just lacking detail).