Which is the correct question form:

John bought a new mobile phone.

• What bought a new mobile phone?

• Did John buy a new mobile phone?

• Who bought a new mobile phone?

• Who did buy a new mobile phone?

John bought a new mobile phone.

• What did John buy?

• Who bought a new mobile phone?

• What did John do ?

• What type of mobile phone did John buy?

John bought a new mobile phone.

• What did John buy?

• Who bought a new mobile phone?

• What does John do?

• What did John do?

John bought a new mobile phone.

• What did John buy?

• What kind of mobile phone has John bought?

• What kind of mobile phone did john buy?

• Who bought a new mobile phone?

Salma goes to university three times a week.

• When does Salma go to university?

• How many times does Salma goes to university?

• How often does Salma go to university?

• Does Salma go to university three times a week?

They've been working for 6 hours.

• Who has been working for 6 hours?

• Who have been working for 6 hours?

• Who was working for 6 hours?

• Who were working for 6 hours?

Adel and Khalid usually go to work by car.

• Who usually go to work by car?

• Who usually goes to work by car?

• Do Adel and Khalid usually go to work by car?

• Who went to work by car?

Adel and Khalid usually go to work by car.

• Who usually go to work by car?

• How does Adel and Khalid usually go to work?

• How do Adel and Khalid usually go to work?

• How did Adel and Khalid usually go to work?

Adel and Khalid usually go to work by car.

• When do Adel and Khalid go to work by car?

• What do Adel and Khalid usually do by car.

• How do Adel and Khalid usually go to work?

• How often do Adel and Khalid go to work by car?

Adel and Khalid usually go to work by car.

• What do Adel and Khalid usually do by car?

• Where do Adel and Khalid usually go by car?

• Where did Adel and Khalid usually go by car?

• Why do Adel and Khalid usually go to work by car?