GRAMMAR

Real Conditionals •  In real conditionals, the verb in the if clause is in the present, even if it has  future meaning. •  Real conditionals can also be formed with the present continuous in the if clause. If you’re going tomorrow, call me.  If it’s raining, I might take the bus. 

•  When an unreal conditional if clause contains the verb be, use were for all subjects

•  Unreal conditionals can also be formed with the past continuous in the if clause. If I were leaving now, I might walk to work. •  See 15.5 for contractions with would.