Unnecessary hyphens are at least as common a problem as omitted ones. Do not hyphenate the parts of a two-word verb such as depend on, turn off, or tune out (43b).

The words pick up act as a verb and should not be hyphenated.

However, be careful to check that the two words do indeed function as a verb in the sentence; if they function as an adjective, a hyphen may be needed (36a and d).

Let’s sign up for the early class.

The verb sign up should not have a hyphen.

Where is the sign-up sheet?

The compound adjective sign-up, which modifies the noun sheet, needs a hyphen.

Do not hyphenate a subject complement—a word group that follows a linking verb (such as a form of be or seem) and describes the subject (37b).