有时为了表达的需要，在虚拟语气中并不总是出现if引导的条件句，而通过其他手段来代替条件句。
常用的词有 with, without, but for, otherwise, or或分词结构，和独立主格结构。如：
I was ill that day. Otherwise, I would have taken part in the sports meeting.
He telephoned to inform me of your birthday, or I would have known nothing about it.
A man who stopped drinking water would be dead in about seven days.
I might have given you more help, but I was too busy.
Everything taken into consideration, they would have raised their output quickly.
