Correct the sentence below by adding the appropriate punctuation WITHOUT changing the wording. I decided to climb the seven flights of stairs Mother took the elevator.

I'm not sure if this is correct but I decided to climb the seven flights of stairs. Mother took the elevator.

basic principle: a pronoun usually refers to something earlier in the text (its antecedent) and must agree in number — singular/plural — with the thing to which it refers. the indefinite pronouns anyone, anybody, everyone, everybody, someone, somebody, no one, and nobody are always singular.