Wah How to use Whether or not.

When we are not sure or we don't care which one is true, we can use Whether or not. 

• I’m not sure whether I can park here or not. (I am not sure that I can park here or I cannot park here.)

And we can say like this:

• I’m not sure whether or not I can park here. 

When we use the word whether, we imply that there will be two things to choose. If the other thing is or not, then you can leave it off, as in:

• I’m not sure whether I can park here. (Because we already know that "or not" means I cannot park here.)

Let's see other examples:

• I don't care whether you come or not. (It does not matter to me whether or not you come.)
• I don't care whether you go or not. (It's all the same to me whether you go or stay.)
• I don't know whether or not I am ready for this surgery. 
• I'm not sure whether or not I locked the door.
• You can come to the baseball game whether you have enough money or not.

I am not sure whether it is a lion or not.

Wah How to use "You are to"

We can use Subject + Be + To when we are talking about responsibilities or duties.
This form has the same meaning as Be supposed to.

• My mom told me that I was to clean up the house before she was back. (I was supposed to clean up the house.)
• My boss says that John is to finish the job by Friday. (John is supposed to finish the job by Friday.)
• The doctor said that I was to start exercising. (I was supposed to start exercising.)
• Employees are to wash their hands after using the toilet.
• Jane is to present her report first.
• My children are to read a book before bed every day.
• The security guards are to ensure that everything is alright.

The police officer told her that she was to drive slowly.

Wah How to use "Between"

Between is a preposition
We use Between when there are only two objects in addition to the object we are talking about, and the object occupies the space somewhere in the middle.

• Mongolia lies between Russia and China.
• The train runs between the town and the airport.
• Please keep this secret between you and me.
• John was standing between Martin and Alex.
• Do you know the difference between right and wrong?

We also use Between when the objects we are talking about are positioned clearly or the relationship they have relative to each other is clearly defined even though there are more than two objects.

• My villa is between the village, the river and the woods.
• There is a disagreement on this issue between the gorverment,the police and the military.
• The trade agreement between Italy, France and Germany was signed last month.

The gulf that is located between Saudi Arabia and Iran is called the Persian Gulf.

Wah How to use "Whereas"

We know that we can use while for contrasting sentences.
And we can also use whereas in written or formal English.

• I am poor, whereas my brothers are very rich.
• Sugar is sweet, whereas lemons are sour.
• Martin is very tall, whereas his bother is short and fat.
• John's job is very interesting and relaxed, whereas my job is boring and stressful.
• I did't enjoy the movie, whereas my girlfriend thought it was great.
• My new car is reliable and economical, whereas my old car was unreliable and expensive to run.
• My father used to walk to work, whereas nowadays he use the car.

Note: We should always use a comma between the contrasting sentences.

Some people believe that schools are responsible for the behavior of their students, whereas others argue that discipline is the responsibility of parents.

Wah How to use Impersonal You / One.

We can use you to refer to people in general.
In these sentences, you doesn't mean one person. 

• You can't believe everything you watch on the television. (People can't believe everything  they watch on the television.)
• You should always be polite. (People should always be polite.)
• You can’t learn a language in two weeks. (People can’t learn a language in two weeks.)
• If you get ill, you should see a doctor.
• If you want to succeed, you should work hard.
• The only place you can get great food is in Thailand.

In formal English, we can use one instead of you.

• One can't believe everything one watches on the television.
• One should always be polite.
• One can’t learn a language in two weeks.
• If one gets ill, one should see a doctor.
• If one wants to succeed, one should work hard.
• The only place one can get great food is in Thailand.

If one fails, then one must try harder next time.

Wah How to use "Be able to"

We use be able to talk about ability. 
We sometimes use it instead of can and could.

• I cannot visit my parents. = I am not able to visit my parents.

We can use be able to in many different forms.

Future Tense

• Tomorrow, he will be able to join our party.  Tomorrow, he will can join our party.  is incorrect.
• Will you be able to go to the park with me next week?
• I am afraid I won't be able to go with you.

Present Perfect Tense

• Simon has been always able to remember his students' name.  Simon has been always can remember his students' name.  is incorrect.
• I have never been able to swim.

Past Tense

• I was able to solve the question this morning. (= I could solve the question this morning.)
• I was able to explain to her.

Infinitive Forms

• John is going to be able to help me.
• You have to be able to speak English if you want to get this job.
• You must be able to understand it. It's very important.

I would like to be able to play the piano. 

Wah How to use It's about time.

We know how to use It's time but it's different than It's about time.
We use It's (about) time + Past tense to talk about something you should have done in the past but you didn't do it in that time. (It is almost too late.)

• It's about time he got a haircut. (Your hair is too long. You should have cut it 3 weeks ago, then you should get a haircut now.)
• It's about time you paid me. (It's 2 month late and you haven't paid me so far, you should pay me right now.)
• It's about time I started learning English.
• It's about time we had a break.
• It's about time you cleaned your shoes.

Note: We don't have to put about in the sentences
          It's time he got a haircut. 
          It's time we had a break.

Let's see the difference between It's time and It's about time.

• It's time for you to wash your car. (Your car is a bit dirty, you should wash it right now.)
• It's about time you washed your car. (Your car is very dirty. You should have washed it last week ago, then you should wash it right now.)

It's about time you get some new clothes.