Type Use General truth, law of nature PRESENT – FUTURE Something possible to happen PRESENT – FUTURE Imaginary situation, something impossible to happen PAST Imaginary situation opposite to the reality Formation If clause Effect clause If + present simple Present simple If + present simple Future simple (will) / imperative / Can / must + bare infinitive (will go, can / must go) If + past simple Would / could / should + bare infinitive (would/should/could go) If + past perfect Would have + past participle (would have gone) Example If you heat ice, it melts  If Mary goes to the supermarket, she will buy pasta  If you go to Italy, you can visit the Coliseum  If I knew that, I would tell you  If I had studied harder, I would have passed the exams Unless Unless you promise me not to tell it, I won’t tell you Suppose / supposing Supposing you won the lottery, what would you buy? Provided / providing (that) Provided you drive carefully, Dad will lend you his car On condition (that) I’ll come on condition that you come, too As / so long as I’ll tell you as long as you don’t tell anybody I, he, she, it was  I, he, she, it were ex If I were you, I wouldn’t it  Were / should / had, used instead of if Were the in London, they would phone Bill (If the were in London, they would phone Bill.) Should you change your mind, call me (If you change your mind, call me.) Had I known he was there, I wouldn’t have gone (If I had known he was there, I wouldn’t have gone.) But for = if it wasn’t for  would go with Patrick to the party, but for Judy If it hadn’t been for Sally