1 .  When’s your birthday?

⇒ What  is your date of birth ?

2. What is Lan’s date of birth?

⇒  When’s Lan birthday ? 

3 . What’s his date of birth?

⇒  When’s his birthday ?

4 . The party will start at three o’clock and finish at nine in the evening.

⇒ The party will last for six hours.

5. Our lessons usually start at seven and finish at eleven thirty in the morning.

⇒ Our lesson usually last from seven to eleven thirty in the morning.

1. When’s your birthday?

->What is your date of birth?

3.What’s his date of birth?

->When’s his birthday?

2.What is Lan’s date of birth?

->When is Lan's birthday ?

4.The party will start at three o’clock and finish at nine in the evening.

->The party will last 6 hours.

5.Our lessons usually start at seven and finish at eleven thirty in the morning.

->Our lessons usually last 4,5 hours

what có nghĩa là “cái gì”, thường được dùng để hỏi tên, đồ vật, nghề nghiệp, … Câu hỏi với what 

cấu trúc là: What + be/trợ từ + S ?