If only I ____ (be) ten years younger!

If only I ____ (be) ten years younger!
我知道答案是 were 为什么?
请哪位高手给解释解释.
were不是are 的过去试吗?

If only I were ten years younger!要是我年轻十岁就好了!
在虚拟语气的从句中,动词'be'的过去时态一律用"were",不用was,即在从句中be用were代替.
If I were you,I would go to look for him.
如果我是你,就会去找他.
If he were here,everything would be all right.
如果他在这儿,一切都会好的.
典型例题
_____ to do the work,I should do it some other day.
A.If were I B.I were C.Were I D.Was I
答案C.在虚拟条件状语中如果有were,should,had这三个词,通常将if省略,主语提前,变成 were,should,had +主语的形式.但要注意,在虚拟条件状语从句中,省略连词的倒装形式的句首不能用动词的缩略形式.如我们可说 Were I not to do.,而不能说 Weren't I to do.
有关虚拟语气资料：
虚拟语气
1）概念
[Subjunctive Mood]
中文译作"虚拟语气".它是一种动词形式,表示说话人的某种假设、愿望、怀疑、猜测、建议等含义.
2） 在条件句中的应用
条件句可分为两类,一类为真实条件句,一类为非真实条件句.非真实条件句表示的是假设的或实际可能性不大的情况,故采用虚拟语气.
虚拟语气的使用范围及判断
一、虚拟语气表示一种不能实现的假设.该语法主要用于if条件状语从句.也可用于主语从句、表语从句、宾语从句等.
二、if条件状语从句中虚拟语气的判断
判断是真实条件句还是非真实条件句.只有在非真实条件句中才使用虚拟语气.通过句子意思,看假设的条件是否能够实现,能够实现是真实条件句,不能使用虚拟语气；假设的条件不能实现则是非真实条件句,要用虚拟语气.
判断这个假设是与哪个事实相反.通常有三种情况：①与过去事实相反.②与现在事实相反.③与将来事实可能相反.
三、“后退一步法”
后退一步法是指在准确地判断了该句与哪一事实相反后,按虚拟语气的后退一步法处理从句谓语动词的时态.即：在非真实条件状语从句中,谓语动词按正常情况“后退一步”.也就是：
①与过去事实相反,在从句中用过去完成时形式表示.
②与现在事实相反,在从句中用过去一般时形式表示.
③与将来事实可能相反,在从句中用过去将来时形式表示.
主句中则用情态动词would,should,could 等加一个与从句一致的动词形式.
例：If I had come her yesterday,I would have seen him.
If I were a teacher,I would be strict with my students.
If it should snow tomorrow,they couldn’t go out.
四、注意事项
①if条件句中如有were,should,had,可以省去if,并使用倒装语序.
②在现代英语中if条件状与从句中的谓语动词如果是be其过去形式一般用were.
宾语从句中的虚拟语气
一、wish 后面宾语从句中的虚拟语气
wish 后面宾语从句中的虚拟语气,按“后退一步法”处理从句的谓语动词.注意：与哪个事实相反,不能以主句的时态为判断依据,而是根据从句的意义判断.
二、表示“要求、建议、命令”等动词后面的宾语从句中的虚拟语气
从句中用“should + 动词原形”构成.而且should可以省去.用于此结构的动词有：advise,direct,agree,ask,demand,decide,desire,insist,order,prefer,propose,request,suggest等.
注意：当insist表示“坚持认为”、suggest表示“表明,显示”时,不用虚拟语气.
The look on his face suggested that he was quite satisfied with what I had done for him.
He insisted that he was honest.
三、would rather ＋从句
在这种结构中,从句的位于动词用过去形式表示虚拟.
I would rather you did this instead of me.
主语从句中的虚拟语气
一、It be + 形容词 + that ．．．（should）．．．
用于该句型的形容词是：necessary,good,inportant,right,wrong,better,natural,proper,funny,strange,surprising ．
一些名词也可以用于 在该结构中.如：a pity,no wonder．．．．
二、It be + 过去分词 + that ．．．（should）．．．．
用于该结构中的过去分词是表示“建议、请求、命令”等词的过去分词.如：desired,suggested,requested,ordered,proposed等.
三、It is time（about time,high time）that ．．．（过去式动词形式或should＋动词原形）．．．．
It is high time I went home now.= It is high time I should go home now.
表语从句、同位语从句中的虚拟语气
在suggestion,proposal,order,plan,idea,advice,decision等需要有内涵的名词后面的表语从句、同位语从句中,要使用虚拟语气.其谓语动词应用：should＋原形动词.另外连接从句的that不能省略.
例：My suggestion is that weshould go there at once.
What do you think of his proposal that we should put on a play at the English evening?