1.表示与现在事实相反的情况时, if从句的谓语用动词的过去式 (be动词的过去式多用were, 而不用was), 主句的谓语用should / would / could / might +动词原形 (should多用于第一人称, would多用于二三人称, could / might可用于所有人称)
2.表示与过去事实相反的情况时, if从句的谓语用had done形式, 主句的谓语用should / would / could / might + have done的形式
3.表示与将来事实相反的情况时, if从句的谓语形式是: ①.完全动词过去式 (be的过去式通常用were); ②.should +动词原形; ③.were to do. 其中②, ③种情况都含有出乎意料之外之意; 主句的谓语的形式是: should / would / could / might +动词原形
If I had a million dollars... Everyday I pray to the god that I wish I could win a million dollars from the lottery. If I had such money. First I would devote half of them to those who had helped me or the poor. Then I would take some of them as a pay for the long-travelling over the world for some very famous places of interests.Then I would buy my parents a house and stay with them to take care of them.