When the real subject is a gerund or an infinitive or a clause, it is used as a provisional subject to begin the sentence. Different verb patterns are possible.
It + be + adjective + of + noun / pronoun + to-infinitive
The adjectives used in this pattern include the following: kind, good, generous, considerate, foolish, stupid, unwise, clever, wise, nice, wrong, polite, brave, cowardly, silly, wicked, cruel, careless etc.
- It is kind of you to help us.
- It was careless of her to leave the keys on the table.
- It was foolish of him to reject the offer.
- It is wicked of him to say such things.
- It was unwise of me to lend him money.
It + be + adjective + to-infinitive
- It is easy to learn English.
- It isn’t easy to give up smoking.
- It is cruel to treat animals in that way.
- It was impossible to reach there in time.
It + be + subject complement + gerund phrase
- It is no use arguing with him.
- It is worth seeing the film.
- It is no use worrying about it.
It + be + adjective / noun + that-clause
- It is strange that she should forget me so quickly.
- It is possible that she doesn’t realize the gravity of the situation.
- It is doubtful whether he will be able to come.
- It is fortunate that you escaped unhurt.
It + take + pronoun + time phrase + to-infinitive
- It took me twenty minutes to reach the station.
- It only takes me two minutes to get ready.
- It took him two months to recover from his illness.
- It took me quite sometime to adjust to the new circumstances.
- It took her ten years to finish her first book.