know about----How long..? and When..? Since and For----of English Grammar.

Compare How long..? (+present perfect) and When..? (+past simple):

1. When did he start reading English Grammar?

2. He started reading English Grammar two hours ago.

1. How long has he been reading English Grammar?

2. He has been reading English Grammar for two hours/since 2 o’clock.

We use since and for to say how long something has been happening.

We use for when we say a period of time (three hours, seven weeks etc.).

And we use since when we say the start of a period (7 o’clock, Sunday etc.).

Unit 2

Know about----Past and present perfect (I have gone and I went) ----of English Grammar.

The present perfect is a present tense. Always it tells us something about now. “Jony has lost his pen” = Jony doesn’t have is pen now.

The past simple always tells us only about the past. If someone says “jony lost his pen”, we don’t know whether he has it now or not. We only know that he lost the pen at some time in the past.

As appropriate English Grammar don’t use the present perfect if there is no connection with the present (for example, things that happened a long time ago):

· The English invented cricket. (not have invented)

Unit 3

Know about----Past perfect (I had gone) ----of English Grammar.

Sometimes we talk about something that happened in the past:

· Karan came to the school.

This is the starting point. Then, if we want to talk about something that happened before this time, we use the past perfect (had..).

· When Karan came to the school, I had already gone to the playground.

Had gone (past perfect) is the past of have gone (present perfect).

Unit 4

Know about----Used to----of English Grammar.

Let’s see the example situation:

Jony stopped reading English Grammar three years ago. He doesn’t read English Grammar any more.

But he used to read English Grammar.

“He used to read English Grammar” = he read English Grammar regularly for some time in the past, but he doesn’t read now.

Something used to happen = something happened regularly in the past but no longer happens:

· I used to go abroad a lot but I don’t go very often now.

· She used to travel a lot. These days she doesn’t go away very often.

Don’t confuse I used to do and I am used to doing. The structures and meanings are different:

I used to smoke = I smoked in the past but I no longer smoke.

I am used to smoking = I smoke and I don’t find it strange or new because I have been smoking for sometime.