Cleft sentences are used to emphasize one part of a sentence in particular. Although they are very useful in writing, where we cannot use intonation for emphasis, they are also used when speaking.
We can emphasize one part of a sentence
👉 The person who broke the glass is waiting outside
👉 The thing which/that I bought was a new book
👉 The place where She found the cat is the kitchen
👉 The day when/that Ana received the news was Monday
👉 The reason why I am studying English is to find a better job.
👉 Why I am studying English is because I want to find a better job
👉 What I found interesting was (to) see him at the conference
👉 What he did was (to) think of a better solution
👉 Where they studied the degree is Florence
👉 All I did was (to) go to the supermarket and buy a few things for the party
👉 All I want is (to) have a peaceful life
👉 What happens is that she doesn’t want to study there
👉 What happened was that they got angry with her
Instead of “the person who, the thing that, etc.” we can use It + to be + phrase + relative
👉 It is your birthday that I enjoy so much = What I enjoy so much is your birthday
👉 It was MarĂa who/that I saw yesterday = Who I saw yesterday was MarĂa
👉 It is this kind of film that makes me cry = What makes me cry is this kind of film
Be careful! We cannot use when with adverbial phrases
👉 It’s Sunday when I see my friends → It’s Sunday that I see my friends
👉 It’s on Sunday that I see my friends → It’s on Sunday when I see my friends