虚拟语气表现形式六
用于“should (would)+动词原形”表示虚拟语气，其中的should用于第一人称，would第二、三人称（但在美国英语中常用would代替should）。如：
But for his pension, he would starve. 要不是他有养老金，他就挨饿了。
She would be perfectly happy if she had a car. 假如她有一辆车，她会十分快乐。
If I were you, I should take his advice. 我若是你，就会听他的忠告。
虚拟语气表现形式七
用于“should (would)+have+过去分词”表示虚拟语气，其中的should用于第一人称，would第二、三人称（但在美国英语中常用would代替should）。如：
The soup would have been better if it had had less salt. 这汤如果少放点盐就好了。
If I had seen her I should have invited her. 我当时要是看到她的话我本会邀请她的。
She would never have been promoted if she hadn’t changed jobs. 她当时要是不调换工作，是永远得不到提拔的。
注意，虚拟语气的动词形式有时也陈陈语气的某些动词时态形式相同，但两者的内涵及其所表示的时间皆不一样，千万不可混淆。