1. REVIEW TENSES

2. PRESENT CONTINUOUS TENSE vs SIMPLE PRESENT
Function: Something happening at / around the time of speaking.
I am doing
past now future
Example:
1. Listen to those people. What language are they speaking?
2. The water is boiling. Can you turn it off?
3. Please be quiet. I am working now.
4. J.K. Rowling is working on her new novel.
Function: Something in general or things that happen repeatedly
I do
past now future
Excuse me, do you speak English?
2. Water boils at 100 degrees Celsius.
3. Jeff works in a very big office.

3. PRESENT PERFECT vs PRESENT PERFECT CONTINUOUS
Function: To express an activity started in the past and has been finished before now. We are interested in the result/achievement of the activity.
Example:
Somebody has smoked all my cigarettes. The package is empty.
Mary has written ten letters today.
3. They have played tennis three times this week.
4. The car is OK now. I have repaired it.
Function: To express activity started in the past, still in progress now, and might continue in the future. We are interested in the activity.
1. She has been smoking too much recently.
2. Mary is still writing letters. She has been writing letters all day.
3. They have been playing tennis since 2 o’clock.
4. My hands are very dirty. I have been repairing the car.

4. SIMPLE PAST vs PAST CONTINUOUS
Function: To express an activity started and finished at certain point of time in the past x
Past now future
Example:
I work in a travel agency now. Before that I worked in a shop.
The police stopped me on my way home last night.
She passed her examination because she studied very hard.
Function: To express that somebody was in the middle of doing something at a certain time in the past.
started doing was doing finished doing
Past past now
This time last year I was living in Brazil.
What were you doing at 10 o’clock last night?

5. SIMPLE PAST vs PAST CONTINUOUS
We often use Past Simple and Past Continuous together to say that something happened in the middle of something else.
Example:
I was walking home when I met Dave. (=in the middle of walking home)
Ann was watching television when the phone rang.
Tom burnt his hand when he was cooking the dinner.

6. PAST PERFECT vs PAST SIMPLE
Function: To express an activity started and finished in the past (before now). We are interested on the result.
had done
past now
Example:
The house was dirty. They had not cleaned it for weeks.
We weren’t hungry. We had just had lunch.
Function: To express an activity started and finished at certain point of time in the past x
Past now future

7. PAST PERFECT vs PAST SIMPLE
Sometimes, Past Perfect and Past Simple are used in a sentence. In this case, actions expressed by Past Perfect happened before the Past Simple.
Example:
When I arrived at your house, Tom had already gone to airport.
1st event: Tom went to airport
2nd event: I arrived
2. The house was very quiet when I got home. Everybody had gone to bed.
1st event: Everybody went to bed
2nd event: I got home

8. Will vs Going To WILL GOING TO
Function: will is used when we decide to do something at the time of speaking. The speaker has not decided before.
Example:
A: Let’s have a party.
B: Cool. I will surely come!
2. X: Ann is in hospital.
Y: Oh really? I didn’t know. I will go and visit her.
Function: (be) going to is used when we have already decided / planned to do something.
Sue and I have decided to have a party. We are going to invite lots of people.
2. X: Ann is in hospital.
Y: I know. I am going to visit her tomorrow.

9. Will vs Going To
Will and Going To can also be used to predict the future
WILL
GOING TO
We use will if the prediction is based on one’s personal opinion.
Example:
Tom will probably arrive at about 8 o’clock.
I think Ann will like the present we bought for her.
We use going to if the prediction is based on the present condition/fact.
Look at those black clouds. It is going to rain.
I feel terrible. I think I am going to be sick.