| Zero: facts | if + present, present | If you mix blue and yellow, you get green. |
| First: real possibilities | if + present, will + V | If you study, you'll pass. |
| B1Second: unreal situations | if + past simple, would + V | If I won the lottery, I'd buy a house. |
| The if-clause | present simple, also for the future | If it rains, we'll stay in. |
| Order | if-clause first: comma; if-clause second: no comma | If it rains, we'll stay in. / We'll stay in if it rains. |
| B1Trap | were for every person, also in advice | If I were you, I'd take the train. |
| B1Trap | unless means if … not; the verb is affirmative | Unless you hurry, you'll miss the bus. |