How is a personal pronoun a subject comlement?

Answer 1

A subject complement is the adjective, noun, or pronoun that follows a linking verb; it is normally an adjective or a noun that renames or defines in some way the subject.

Keep in mind that a personal pronoun used as the subject complement must be an objective pronoun as object of the linking verb. Using the famous Pogo Possum quote as the example:

"We have met the enemy and he is us."

Answer 2

A personal pronoun can serve as a subject complement when it follows a linking verb and renames, describes, or identifies the subject of the sentence. For example, in the sentence "She is my sister," "my sister" is the subject complement that describes the subject "she."