If the verb is an action that is currently taking place, you would use the present tense with a third person pronoun. For example, "He is reading a book."
If the verb is an action that happened in the past, you would use the past tense with a third person pronoun. For example, "She went to the store yesterday."
If the verb is an action that will happen in the future, you would use the future tense with a third person pronoun. For example, "He will visit his parents next week."