急问：IF 和 ONLY IF

lost_my_account

ONLY IF是表示充要关系吗？

哪位NN可以把这些表示关系的连接词和短语列一下？

谢谢！

Andrea625

我觉得only if是必要的，不一定是充要的。

only ongman--- used to say that something happens or is possible in one particular situation or place and no others, or for one particular reason eg.
I'll tell you, but only if you don't tell anyone else.   I ate the food, but only because I was starving.   The transfer takes place only when the data is complete.

ifongman -- 3. used to mention a type of event or situation when talking about what happens on occasions of that type ; eg.Plastic will melt if it gets too hot.

   MW-- 1 a : in the event that  b : allowing that  c : on the assumption that  d : on condition that

[此贴子已经被作者于2004-7-7 8:40:20编辑过]

WONDERLAND2004

Only if 是充分条件。我是这么理解的，xdf的霏霏也是这么说的。
I'll tell you, but only if you don't tell anyone else. 指“如果我告诉你了，必然可以退出你不会告诉任何其他人”。
if only才是必要条件。
这样对不对？ 请nn们指教。

lost_my_account

谢谢。。

我觉得ONLY IF 是必要条件。。