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 link sentences with While.

1. We can use while to join two related sentences.

• Panda live in China, while the Koala live in Australia.
• The meat of snake was used for food, while the skin were used to make boots.
• I find new customers, while Mary manages the store.
• Jason has got promoted to a Manager, while his wife has become a CEO. 

2. We can also use while for contrasting sentences.

• Many people like John, while some doesn't like him.
• Many people believe there is no one live in the desert, while the reality is quite different.
• While in summer the weather is very hot, in the winter it is very cold.
• While I like all types of fish, my girlfriend always chooses meat dishes when we go out to eat.

A lot of people prefer traveling by plane, while others choose the train.

Wah How to use Past Continuous and Past Simple.

We use Past Continuous and Past Simple forms to describe two event in the past which happen at the same time.

We use Past Continuous to indicate that a longer action in the past that was interrupted.
We use Past Simple for a single action that take a short time to interrupt the longer action in the past.

• I was watching a television when the phone rang. 
• While we were sleeping, it started to rain.
• She was cooking dinner when I got home.
• I got to the office while Sara was just making some coffee.
• The computer suddenly went off when I was writing the email.
• I was attending the conference when I met my ex-boyfriend.
• What were you doing when John arrived?
• What were you doing when the lights went off last night?

When and While
We use when before Past Simple.
We use when or while before Past Continuous.

It was snowing when I went home.