It is + adj. + (for sb) to do sth.
It is important for us to learn English well.
It is necessary for him to study hard for the exam.
It is + adj. + that + 句子.
It is amazing that she passed the driving test.
It is interesting that they are traveling around the world.
It is + adj. + to do sth.
It is helpful to review the lesson before the exam.
It is necessary to improve your communication skills.
It is + adj. + of sb (not) to do sth.
It is kind of him to help us with the project.
It is irresponsible of them not to finish the task on time.
It 作为形式宾语
It + v. + (sb) + (时间/地点) + to do sth.
They find it difficult to understand the complex math problem.
I consider it important to keep a healthy lifestyle.
It + v. + sb + (时间/地点) + to do sth.
I find it interesting to watch movies on weekends.
She considers it relaxing to read books in the park.
It + seems/appears + (that) + 句子.
It seems that she knows the answer to the question.
It appears that they have a good plan for the project.
It 作为强调句型
It is ... that/who + 句子.
It is Jane who won the first prize in the singing competition.
It was his hard work that helped him achieve success.
It is not until + 句子 + that + 句子.
It is not until you face your fears that you can overcome them.
It wasn't until she apologized that he forgave her.
It 作为形式表语
It + be + n. + to do sth.
It's my duty to take care of my younger siblings.
It's a pleasure to meet you.
It + be + adj. + for sb + to do sth.
It's necessary for us to learn a foreign language.
It's important for children to have a balanced diet.
