Pronoun Agreement

The pronoun must agree in number with its antecedent:

The players all cheered. They were very happy to win.

The goalie cheered. He was elated to score a goal.

The pronoun as subject must agree with the verb:

He was elated and they were happy.

Personal pronouns must be in the proper case:

Subjective case:

I flew to Paris.

Objective case:

Fate took me to Rome.