英语问题现在完成进行时是哪样的?用法呢?由if的句子怎样用,否定怎样回答

英语问题
现在完成进行时是哪样的?用法呢?由if的句子怎样用,否定怎样回答

Present perfect continuous 现在完成进行时
请看下面的例句:
Is it raining ? No, but the ground is wet. It has been raining.
我们用现在完成进行时表示最近停止或刚停止的动作(We use the present perfect continuous for an activity that has recently stopped or just stopped.).
You’re out of breath. Have you been running ? (you’re out of breath now)
Paul is very tired. He’s been working very hard. (he’s tired now)
Why are your clothes so dirty ? What have you been doing ?
I’ve been talking to Carol about the problem and she thinks that …
It is raining now. It began raining two hours ago and it is still raining.
How long has it been raining ? It has been raining for two hours.
我们常这样用现在完成进行时,特别是和“how long,for,since” 这个动作可能仍然在进行（以上这个例子里）或刚刚停止.We often use the present perfect continuous in this way, especially with how long, for… and since…The activity is still happening(as in this example) or has just stopped.
一些练习
第一题：填入正确的时态
arrive,break,go up,grow,improve .lose
1. Mike is looking for his key. He can’t find it.He_______________
2. Margaret can’t walk and her leg is in plaster.She_______________
3. Maria’s English wasn’t very good. Now it is much better._________________
4. Tim didn’t have a beard last month. Now he has a beard._____________________
5. This morning I was expecting a letter. Now I have it._________________
6. Last week the bus fare was 80 pence. Now it is 90.____________________
第二题：填入以下单词的正确形式
1. Joe goes out. Five minutes later, the phone rings and the caller says’ Would you like sth to eat ?’You say: No, thank you. I______________________(have lunch).
2. Maria_______________________(learn) English for two years.
3. Why _____________________(you/look) at me like that ? Stop it!
4. You are going to a restaurant this evening. You phone to reserve a table. Later your friend says ‘Shall I phone to reserve a table ?’ You say: No,_________________________it(do).
5. ‘Is Ann on holiday this week ?’ ‘No, she_____________________(work).’
6. Hello, Tom. I _____________________________(look) for you all morning. Where have you been ?
---------------------------------------------------答案：
一：
1. He has lost his key.
2. She has broken her leg.
3. Her English has improved.
4. He has grown a beard.
5. The letter has arrived.
6. The bus fare has gone up.
二：
1. he’s just gone out.
2. has been learning
3. are you looking
4. I’ve already done
5. is working
6. have been looking
有if的句子一般是虚拟语气,而虚拟语气一般都是假设的情况,就是否定.
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?