It is (high) time后接簡單過去式，表示早該是...的時候了。

It is (high) time that I left.

我早該走了。

在假設(shè)語氣結(jié)構(gòu)里有時可以省略副詞子句，條件一般暗含在片語或上下文里。

Alone by myself, I wouldn’t have been delighted.

如果我單獨一個人我是不會感到愉快的。

假設(shè)語氣中的副詞子句可以省略連接詞if，此子句中的助動詞had, were, should等要移至主語之前。

Were I Jane, I would be very pleased to marry you.

如果我是珍,我會很高興嫁給你。

would that相當于how I wish。

Would that Jane accepted my proposal.

珍要是接受我的求婚就好了。

Even if...表示即使...也。

Even if you failed again, you shouldn＇t give up.

即使你再次失敗，你也不應放棄。

may+原形動詞是假設(shè)語氣的一種形式，表示祝愿。

May you succeed!