“be+不定式”表示虛擬語氣

即用于與事實相反的虛擬條件句，表示虛擬語氣。此時be通常要用were這一形式，但在非正式文體中也可用was。如：

I’d be sorry if you were to think that I disliked you. 若是你認(rèn)為我不喜歡你，那我就太傷心了。

If it were to rain, we would have to cancel the match tomorrow. 假如下雨, 我們只好取消明天的比賽。

注意其省略倒裝形式：

If I were to tell you / Were I to tell you that I killed him, would you believe me? 假如我對你說是我殺死了他, 你相信嗎?

If I were to do that / Were I to do that, what would you say? 如果我做了那件事，你會說什么呢?