2. 1- Remember that we use this tense to
describe facts and regular events.
It is used a lot in science.
In science, it is often used in the passive.
The passive is used when the action is important, not the people.
PASSIVE
This tense used
by scientists.
ACTIVE
Scientists use this
.tense for facts
3. 2- In questions, negatives and short answers ,we use helping verbs.
ACTIVE
DO scientists use this
tense for facts?
Yes ,they do.
PASSIVE
Is this used
by scientists?
Yes , it is
4. 3- Sometimes we think the answer to our question will be Yes .
Sometimes we think it will be No.
We make these questions by adding helping verbs to the end of our
sentence.
ACTIVE
Planets reflect light , don`t they?
Yes ,they do .
A planet doesn’t radiate light, does it ?
No, it doesn't
PASSIVE
Light is reflected by planets , isn't it?
Yes, it is
Light isn't raidated by planets is it?
No , it isn't
5. Exercises:
A. In the following sentences , the dark words (e.g. a
planet) are singular.
Rewrite the sentences making the dark words plural ( g. a
planets) . Change the verb if necessary.
1-A planet reflects light.
Planets reflect light.
2-Does a planet orbit a star ?
Do planets orbit a star?
6. B. Write the following sentences again . Put the
verbs into the correct form .
1- I (be) at school .
I am at school.
2- Our sun (be) a star .
Our sun is a star.
7. C . Make the following sentences negative.
1- Stars reflect light.
Stars don`t reflect light.
2- Venus has a moon.
Venus doesn`t have a moon.
8. D. Make these sentences passive.
1-Scientists study the universe.
The universe is studied by scientists.
2- Do stars radiate light?
Is light radiated by stars?
9. E . Make these sentences into questions .
Expect the answer in brackets.
1- There is only one star in the Solar System. (Yes)
There is only one star in the Solar System, isn`t
there?
Yes, there is.
2- There aren`t people on Venus. (No)
There aren`t people on Venus , are there?
No, there aren`t.
