有关虚拟语气的疑问（涉及be
虚拟语气是一种特殊的动词形式，一是用来表示说话人所说的话不是一个事实，而是一种假设、猜测、怀疑等(在条件从句中或让步状语从句中)；一是表示说话人的愿望、要求、命令、建议等 (在宾语从句、表语从句、同位语从句)。
虚拟式仅有两个形式：
【一】be-型虚拟式（BE-Subjunctive);
【二】were-型虚拟式（WERE-Subjunctive)。
【一】be-型虚拟式的主要用法
【1】用于表示命令、决定、建议等词语之后的that-分句中。
命令性虚拟语气在美国英语中用得较多。在英国英语中，它用在正式的和相当严格的法律语体中。
The employees have demanded that the manager resign.
尤其是美国英语
The employees have demanded that the manager should resign/resigns.尤其是英国英语
He ordered that all the books be sent at once.
It is essential that all the facts be examined first.
The board has given instructions that the agent fly to Boston.
She insists that he is guilty of fraud.
We insist that he be admitted to hospital immediately.
insist后面是否用虚拟语气，取决于意义。当这一动词引导的是一个间接陈述句时，就用陈述语气，但当它引导的是一个间接的命令句时，则多半用虚拟语气。suggest也有类似的用法。
I insisted (required) that he (should) change his clothes.
I insisted (asserted) that he changed his clothes.
She suggested (recommended) that I (should) be responsible for the arrangements.
She suggested (said tentatively) that I am responsible for the arrangements.
【2】用于由 if, though, whatever, lest, so long as 等引导的分句中。表示推测让步，防备等含义。
If he be found guilty,John shall have the right of appeal.
上述用法现在只限于正式书面语体，在非正式语体中通常用动词陈述式或者should/may+不定式。
If the rumour is true,everything is possible.
【3】套语式虚拟语气和命令性虚拟语气一样，由动词原形构成。它主要用在独立分句中的某些固定结构中：即用于某些公式化语句中可表示祝愿、诅咒、禁止等意义。
Come what may, we will go ahead with our plan.
God save the Queen! (May God save the Queen)
Suffice it to say that we won. (Let it suffice…)
Heaven forbid that I should let my own parents suffer.
Be it noted that this offer was made in good faith.
Be that as it may, we have nothing to lose.
Long live the People’ s Republic of China!
God bless you!
Heaven damn you!
Devil take him!
So be it!
备注：套语式虚拟语气在语体上往往显得很正式而过分守旧。
【二】were-型虚拟式的主要用法：
【1】常用于由if , if only , as if , as though , though 引导的条件状语和让步状语分句中，表示非真实的条件或让步。
If I were you , I should wait till next week.
If it were to rain , the game would be put off.
if only是if的强化形式，主要用于假设条件分句，表示讲话人所祈愿的事情会发生、正在发生或者早该发生：
If only you would help me next week, I would not be so nervous.
If only they were here now, we would be able to celebrate their wedding anniversary.
If only somebody had told us, we could have warned you.
条件分句有时单独使用，表示一种假设的祈愿：
If only I’d listened to my parents!
I wish I had listened to my parents.
If only he were not so timid!
If only I could make them understand my point of view!
If only I hadn’t lost it!
only if组合则多用于开放条件句。
条件分句中，有时不用一般现在时态而用现在时虚拟语气来表示开放条件：
If any vehicle be found parked on these premises without written permission, it shall be towed away at the expense of the vehicle’s owner.
If any person be found guilty, he shall have the right of appeal.
这种用法主要限于十分正式的、法律的或准法律的语境中。
我们也可以不用从属连词而用主语-功能词倒装来标明条件关系。在条件分句中，这种倒装形式用得最多的是功能词had：
Had I known, I would have written before.
当分句是否定句时，not置于实义动词之前，不可用前接成分：
Had I not seen it with my own eyes, I would not have believed it.
在多少带有一点文学色彩的语体中，虚拟语气的were和试探性的should也可用倒装形式：
Were it to reveal its secrets, that house would collapse in shame.
Were she in charge, she would do things differently.
Should you change your mind, no one would blame you.
Should she be interested, I’ll phone her.
在另外某些含假设意义的结构中，必须用假设过去时或假设过去完成体：
It’s time you were in bed.
I wish this bus went to the university.
If only I had listened to my parents!
在其他一些也有假设意义的结构中，它们则具有随意性：
He acts as if he knew you.
It’s not as though we were poor.
Suppose we told her the truth.
Imagine your child played truant.
I’d rather we had dinner now.
一般来说，我们可以对这些句子作否定的推论，在用假设过去完成体时，否定意义更强。表示探询式的礼貌，而不是假设的意义。
限制性关系分句和其母句，如果是指某种假设情景的话，则采用和假设条件句相同的形式：
Any person who had behaved in that way should have been dismissed.
除would之外，其他情态助动词也可用于假设条件句中，如有could, might和should。
It they would help us, we could finish early.
If we had enough money, we could buy a typewriter.
If you could type, you might save a lot of time.
I might have married her if she would have agreed.
If they had asked me, I would have had to speak.
If he had apologized, you should have done so too.
Were-虚拟语气表示假设或不真实的含义，用在由诸如if, as if, as though, though之类的连词所引导的状语分句中，也用在像wish和suppose这样的动词后面的名词性分句中。这种虚拟语气只有were这一形式，因此打破了陈述语气动词be过去时第一人称和第三人称单数主谓一致的规则。陈述语气形式was，在不太正式的语体中可用来代替were：
If I were/was rich, I would buy you anything you wanted.
Tim always speaks quietly on the phone, as though he were/was telling a secret.
I wish the journey were/was over.
Just suppose everyone were/was to give up smoking and drinking.
在固定短语as it were(可以这么说)中，不能用was代替were。
让步分句
在正式语体中，现在虚拟式在十分偶尔的情况下可用于让步分句和目的分句。
它们更经常使用的是一般现在陈述式。
Though he be the president himself, he shall hear us.
They removed the prisoner in order that he not disturb the proceedings any further.
Even if that be the official view, it cannot be accepted.
Whatever be the reasons for their action, we cannot tolerate such disloyalty.
Whether she be right or wrong, she will have my unswerving support.
让步分句主要由although或其较非正式的变体though引导。与让步分句连用的其他从属连词有：
if, even if, even though, when, whereas, while, whilst
表示目的限定分句由so that或so和in order that引导。
由lest, in case或for fear that引导的否定目的分句:
The president must reject this proposal, lest it cause strife and violence.
They left early for fear that they would meet him.
They evacuated the building in case the wall collapsed.
for fear (that) 需要一个情态助动词，但in case不需要，古体lest需要一个情态动词或现在时虚拟语气。
Earthen mounds were being hastily erected lest an attack should be/be launched that night.
开放条件（open condition）是中性的，即该条件的实现与否悬而未决，因而由母句所述判断的真实性也无定论：
If Colin is in London, he is undoubtedly staying at the Hilton.
假设条件（hypothetical condition）则表示讲话人相信条件不会满足（将来条件），没有满足（现在条件）或未曾满足（过去条件），因而母句所述的判断可能或当然是虚假的：
If he changed his opinions, he’d be a more likeable person.
(He very probably won’t change his opinions.)
【2】常用于wish , would , rather , suppose , imagine之后的that-分句中，表示一种臆想的情况。
I wish it were spring all the year round.
I ’ d rather I were not at the site of the accident.
上述 were-型虚拟式在第一、三人称单数主语之后可为 was 所取代。
If it was to rain , the game would be put off.
If only I was not so nervous!
但是，在 if I were you 这一分句中，通常倾向于用 were ，而不用 was 。另外，在某些倒装结构中只用 were ,不用 was 。
Were I to do it (= If I were to do it ),I should rely on you.
还有，在 as it were （作 so to speak 解，即“宛如”、“好比”）结构中也只用were ，不用was。
He is my best friend ,my second self ,as it were.