Tips for Grammar

Present Perfect

Positive
Subject to have past participle
She has finished.
Negative
Subject to have + not past participle
She hasn't finished.
Interrogative positive
to have subject past participle
Has she finished...?
Interrogative negative
to have + not subject past participle
Hasn't she finished...?

The present perfect is used for a complete action: We are thinking of the result when describing:

1. An action or situation that started in the past and continues in the present.
I have lived in Canada since 1984. (and I still do)

2. An action performed during a period that has not yet finished.
She has been to the doctor twice this week. (and the week isn't over yet)

3. A repeated action in an unspecified period between the past and now.
We have visited London several times.

4. An action that was completed in the very recent past (expressed by 'just')
I have just finished my work.

5. An action when the result is very important but the time is not.
He has seen ‘Harry Potter’.

Present perfect OR past simple?
Very Important: When we want to give or ask details about when, where, who, we use the simple past.
Example: He saw ‘Harry Potter’ last week.

1. I'm very hungry. I______________________ all day.
a)didn't eat
b)haven't ate
c)haven’t eaten
d)have been eating

2. Their new kitchen looks fantastic. They ________ completely ________ it.
a)have been redecorating
b)have redecorated
c)already redecorated
d)didn't redecorated

3. Our kitchen’s a mess. We____________________ any cleaning for weeks.
a)didn't do
b)haven't been doing
c)have done
d)haven't done

The anwers: 1. (C), 2. (B), 3. (D). The explanation is in the first four points in the begining.

Nouns contables and uncontables


Countable nouns:
Most of the nouns are countable. You can combine them with numbers, e.g one, two or three. Here is an example:
one pencil
two pencils
three pencils
etc.

Uncountable nouns:
These nouns can't be combined with numbers. Here is an example:
water
If you want to express a quantity, you have to use a special phrase e.g. a glass of water.

NOTE:
Some nouns can be either countable or uncountable. We recommend to use a good dictionary. Here is an example, too. hair - hairs
You've got some hairs on your T-shirt. (There might be 5 or 6 of them.)
Your hair looks lovely. (Here you think of the hairstyle.)

Select the wrong answer:
1.- A pack of wolfs can encircle and kill a moose.
a) A
b) wolfs
c) encircle
d) moose

2.- Three species of the fruit bat have been found to have a primatelike visual systems.
a) the
b) bat
c) to have
d) systems

3.- Aeronautical histonian have conclude that the Frenchman Clement Ader made a short leap but never a sustained flight.
a) historian
b) the
c) leap
d) flight

The correct answer: 1. (b) the correct is wolf because is only one, 2.(d) the correct is system because is only one, 3. (a) the correct is historians because is more than one.