If 假設語氣 conditionals = If / when

If 假設語氣 conditionals = If / when

依照可能發生的程度，來使用那一種用法

100% 一定會發生；不管過去，現在，未來
Zero  :  If ice melts , it becomes water.
scientific

50% 極有可能發生
First : If I go to the movies, I will eat popcorn.
   probable                                 may
                                                     might
                                                     could
0% 不太可能發生(與現在事實相反)
second :  if I went to USA this weekend, I would go shopping.
                  if she were here , she would know the answer .

0% 一定不會發生(與過去事實相反), 發生時間為過去
third : if we had hurried, we wouldn't have missed the plane.
             I wish I hadn't make the mistake.

混和
mixed: If i had married Joanne, I'd be happier now.
              If I hadn't drunk so much alcohol last night, I wouldnot be feeling so bad today.