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 (60b).
The words pick up act as a verb and should not be hyphenated.
However, be careful to check that two words do indeed function as a verb in the sentence (31b); if they function as an adjective, a hyphen may be needed.
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 (31k).