Grammar: Continuous Tense(语法：进行时)
1．一般时态和进行时态的区别
1) 一般时态通常表示经常的动作或状态，而进行时态则表示某一时刻或某段时间正在进行的动作。
We read newspapers everyday.
I am reading a newspaper now.
2) 一般时态表示主语的固有特征、能力等，而进行时态则表示主语在某一时刻或某段时间内的具体动作。
The boy sings well.
The boy is singing a folk song.
2．现在进行时 (Present Continuous Tense) 的用法：由助动词am, is are 加现在分词构成.
1) 表示说话人此刻正在进行的动作。
What are you doing? – I am reading.
Li Hong is listening to the radio.
2) 表示现阶段正进行的动作，虽然此刻这个动作可能并不在进行。
They are compiling (编译) a Chinese-English dictionary.
3) go, come, stay, leave, start等动词其进行式有时可表示即将发生的事。
He is coming tomorrow.
4) be going to do…看似进行时形式但表示将来的概念。
I am going to work in Tibet.
He is going to be our boss.
3．过去进行时 (Past Continuous Tense) 的用法：由was (第一、三人称单数) 和were (其余人称和数) 加现在分词构成。
1) 表示过去某一时刻或阶段正在进行的动作，往往有明确的时间状语。
She was reading a magazine when I came into her room.
Last year this road was being built. Now it is finished.
2) go, come, stay, leave, start等表示动作的动词其形式是过去进行式，但有时表示 即将来发生的事。
They wanted to know when the holiday was coming.
3) be going to do…看似进行时形式但表示将来的概念
Our new manager arrived yesterday and was going to interview every employee.
4．将来进行时 (Future Continuous Tense) 的用法：由助动词的将来式既shall be (一人称) 和 will be (第二、三人称) 加现在分词构成。
1) 表示将来某一时刻或阶段正在进行的动作。
What will you be doing this time tomorrow?
-- I will be helping my brother with his homework.
2) 按计划即将发生的动作。
We shall be having a meeting in a minute.
5．过去将来进行时 (Future-in-the-past Continuous Tense) 的用法：由 should be (第一人称) 和 would be (第二、三人称) 加现在分词构成。
1) 在过去某个时间点上看将来某一时刻正在发生的动作。
My uncle once asked me what I should be doing on my graduation.
They said they would be waiting for us at the gate of the school.
2) 表示在过去某一时间之后即将进行的动作。
My hostess said that she couldn’t come to the party because she would be having a meeting.