I Real conditional: 句式为（if + 从句，+主句）1. 主现从现（rule）If the moon goes near the earth, the tide goes high. 2. 主将从现If it stops raining later this afternoon, we will eat out.3. 主祈从现。If you are not likely to be in town, please let me know. II Unreal conditional-背完这些句子你就无敌了1. Aif条件句主句与现在事实相反did（be动词用were）主语 + should/ would /could/ might do与过去事实If + 主语 + had done主语 + should/ would /could/ might have done与将来相反did/were to do/ should do 主语 + should/ would /could/ m
