G1: write the rule. Do not just write "G" or "Glossary of usage" in your corrections. Find the appropriate section in the alphabetized list below, read it, write the rule (or a short version of the rule), and correct the error.

unbelievable: overused as a hyperbole for "good." It means "too improbable to believe":

WRONG: My mother bakes unbelievable pies.

RIGHT: His UFO story is unbelievable.

use to: sometimes used mistakenly for used to. "She used to be my girl friend."