[句型25]It’s+adj+of sb to do sth 【要点精讲】此句型中it是形式主语,of sb是逻辑主语,to do sth是真正的主语,当表语(即形容词)能对逻辑主语进行描述时(即表语为说明人物特点的形容词时),常用介词of,而不用for。例如:It’s very polite of you to give your seat to [Sentence 25] It’s + adj + of sb to do sth [Key points] In this sentence it is a formal subject, of sb is a logical subject, to do sth is a real subject, when the predicative (adjective) can When describing the logical subject (that is, the adjective that describes the characteristics of the character), the preposition “of” is often used instead of for. For example: It’s very polite of you to give your seat to