主语+is/are+doing/形容词/名词
进行时表示动作正在进行,这个动作是暂时的,也是未完成的.进行时包括现在进行时、过去进行时和将来进行时.
A．现在进行时
1．现在进行时的构成
现在进行时是由“am, is, are +现在分词”构成的.
I'm reading the evening newspaper.
我正在看晚报.
Now it isn't snowing outside.
现在外面不在下雪.
Are they playing soccer in the playground?
他们正在操场上踢足球吗?
2．现在进行时的用法
①现在进行时的基本用法
a.表示说话的此刻正在进行的动作
通常由表示“此刻”的时间状语（now, at this moment）,或通过Look/Listen!这两个提示语来表明此时此刻动作正在进行.
She is making a fire now.
她正在生火.
Listen! Mary is singing an English song in the classroom.
听!玛丽正在教室里唱英文歌.
b.表示现在时间段中正在进行的动作
They are planting trees on the hill these days.
这几天他们正在山上种树.
I don't really work here; I am just helping out until the new secretary arrives.
我并不在这儿工作,我只是在新秘书来之前帮帮忙罢了.
c.表示按计划或安排将要发生的动作
能这样用的动词并不多,通常是arrive, begin, come, do, drive, fly, go, leave, stay等表示位置转移的动词.这种用法比较生动,给人以一种期待感.
Jane and Betty are going on holiday in a few days.
几天后简和贝蒂将出去度假.
Where are you staying in Guangzhou?
你到广州后准备住在哪里?
②现在进行时的特殊用法
a.表示一种重复的动作,带有“厌恶”、“赞叹”等感情色彩
现在进行时往往与constantly, always, forever等状语连用,给现在的动作披上一层感情色彩.
She's constantly complaining.
她不停地抱怨.
My brother is always leaving things about.
我弟弟总是乱丢东西.
He is forever thinking of doing more for the students.
他总是想着为学生多做些事情.
b.表示某一具体动作或心理状态的发展过程
The house is falling down.
房子正在倒下.
The weather is changing for the better.
天气慢慢转好了.
注意：
有时表示一个动作刚刚开始.
I'm forgetting my English.
我的英语开始忘了.
Food is costing more.
食品贵了起来.
c.强调动作的重复
The train is arriving late almost every day this summer.
这个夏季火车几乎天天晚点.
Someone is knocking at the door.
有人不断地在敲门.
The boy is jumping with joy.
那男孩高兴地跳个不停.
d.表示两个动作是同一动作
He who helps others is helping himself.
帮人就是帮自己.
If you insist on doing it, you are doing a foolish thing.
如果你坚持做这件事,你就是在干傻事.
e.be动词的进行时态
be动词一般不用于进行时态.但有时可用“am, is, are + being +形容词”结构表示暂时或故意如此.
The boy is being naughty.这孩子有点儿淘气.
I don't think you are being fair.
我认为你不公平.
He is being modest.
他现在很谦虚.
比较：
You are not polite.
你不讲礼貌.（一贯如此）
You are not being polite.
你可有点儿不礼貌了.（暂时的现象）
3．不用进行时态的动词
①表示状态的动词
这类动词有seem, look, appear, have, belong to, own, hold等.
This backpack belongs to me.
这背包是我的.
He seems rather angry with you.
看起来他很生你的气.
②表示知道、信念、理解、推测、怀疑、希望等含义的动词
这类动词有know, remember, understand, see, think, believe, suppose, hope, doubt等.
I don't think he will come tomorrow.
我想他明天不会来.
I still remember the days when we studied together.
我还记得我们一起学习的那些日子.
提示：
有时这些动词的进行时态可表示心理状态的缓慢发展过程.
She's understanding you better now.
她越来越了解你了.
③表示要求、心愿等意义的动词
这类动词有want, wish, need, desire等.
Your clothes need washing.
你的衣服需要洗了.
How I wish I were a bird!
我多希望我是一只鸟啊!
④表示继续或持续含义的动词
这类动词有continue, keep, last, go on等.
She still continues in poor health.
她仍然身体很差.
Every day after finishing his homework, he goes on to do some reading.
他每天做完作业后,都会继续看会儿书.
⑤表示感觉的动词
这类动词有see, hear, smell, taste, feel等.
The apples taste good.
这些苹果尝起来不错.
This flower smells nice.
这花闻上去很香.
Your suggestion sounds reasonable.
你的建议听上去有道理.
注意：
如果这些动词表示一种有意识的行为,则可用进行时态.
She is tasting the apple.
她正在尝苹果.
The dog is smelling the footprints.
狗正在嗅脚印.
The bell is sounding for dinner.
晚饭铃响了.
