Abstract:An English pronoun is a word which can be used instead of a noun, but it has characteristics different from a noun. Pronoun concord should be paid attention to in number, gender and person, especially when its referents are coordinate structures, collective nouns and indefinite pronouns. As for pronoun case form, in practical use, the subjective case form is not always used as the subject, and the objective case form not as the object in modern English. An idiomatic expression in English must first be considered.