but for一定要與虛擬語氣連用嗎

假若but for表示if it were not for或if it had not been for這樣的意思（即表示“若不是”“要不是”），它一定要與虛擬語氣連用。如：

But for his pension, he would starve. 要不是他有養老金，他就挨餓了。

But for the storm, we should have arrived earlier. 要不是碰到暴雨，我們還會早些到。

But for your help we couldn’thave succeeded in the experiment. 如果沒有你的幫助，我們的實驗是不會成功的。

如果but for不是表示if it were not for或if it had not been for這樣的意思，而是構成not for…but for…這樣的搭配，或其中的but只是一個普通的轉折連詞，其后的for也只是一個普通的介詞，此時顯然不必與虛擬語氣連用。如：

I’m not afraid for me, but for the baby. 我不是為我擔心，而是為寶寶擔心。

We don’t usually accept checks, but for you we’ll make an exception. 我們通常接受支票，但對你我們可以破例。

The sale was supposed to last for a week, but for all practical purposes it’s over. 減價銷售原來預料要持續一周，然而實際上現在已經結束了。

You’ll have your own office soon but for the time being you’ll have to share one. 你很快就有自己的辦公室了，不過暫時還得和別人合用一間。