和时态、语态一样,语气(mood)也是谓语动词的一种形式,它表明说话目的和意图。英语中有四种语气,即:
陈述语气(Indicative Mood,或称 Declarative Mood)
疑问语气(Interrogative Mood)
祈使语气(Imperative Mood)
虚拟语气(Subjunctive Mood)
用来陈述一个事实,或提出一个看法,如:
China is a great country. (陈述事实)
It's probably going to rain. (提出看法)
用来提出问题,如:
Where are you from?
Are you from the south?
祈使句的谓语动词都用动词原形(主语省略),称为祈使语气。这种句子可以提出请求,发出邀请,给予指示、忠告或警告,也可发出命令等:
Come in and take a seat. (邀请)
Go there right away. (命令)
Stay in bed for a couple of days. (叮嘱)
Try to talk this over with your sister. (建议)
Stay away from these people. (劝告)
Someone fetch a pail of water.
You girls stand in the front row.
Fasten your seat belt, Tom.
Come this way, madam.
Don't lose the key.
Don't be silly!
在表示一种假想的情况或主观愿望时,动词有时需用特殊形式,称为虚拟语气。涉及的动词形式包括动词原形、情态动词、过去式及过去完成式。在形式上它大致分为三类:
主要是用情态动词或省略后的动词原形,用意是表达需要做或发生的事情,其可能性一般:
They propose(d) that Dr.Wood be elected.
Our decision is that the school remain closed.
主要是 were和过去式,用于各种人称,表示一种估计或期望,其可能性更低一些:
I wish the bus went to the university.
If he found a patient listener, he would pour out his trouble.
① 和过去完成时形式相同,表示已完成,已过去,现在无可能:
If only I had listened to my parents!
I wish I hadn't wasted so much money.
② 有些情态动词也常用在虚拟语气中:
If only she would go with me!