Noun clauses can serve as subjects or objects and often begin with one of these relative pronouns: that, what, whatever, which, whichever, who, whoever, whom, whomever, whose. Logically, you should use subjective case pronouns in noun clauses that function as subjects and objective case pronouns in noun clauses that function as objects. See Chapter 20 "Grammar", Section 20.3 "Choosing the Correct Pronoun and Noun Cases" for a review of pronoun cases.
Subjective Case Example: Joshua Tree National Park, which is in California, is named after a tree that is actually a member of the lily family.
Objective Case Example: A Joshua tree looks like neither its relative, the lily, nor the biblical figure, Joshua, whom the tree is said to be named after.
Adjective clauses modify nouns and pronouns that usually immediately precede the clauses. Adjective clauses often begin with these relative pronouns: that, which, who, whom, whose.
The Mohave and the Colorado are the two deserts that meet in Joshua Tree National Park.
Often adjective clauses leave the relative pronoun implied, as in the following example: I couldn’t get the stain out of the pants (that) I wore to the party.
For more on how to punctuate clauses properly, see Chapter 18 "Punctuation", Section 18.1 "Using Commas Properly".
Complete these steps for the following sentences: