They watch tv in the evening
the boys are singing a nice song
me mother has bought a tasty cake
(задать (специальный опрос, к подлежащему, специальный, выбора, разделительный))

1 They watch TV in the evening.

When do they watch TV?

Who watches TV in the evening?

Do they watch TV in the evening?

(Это общий вопрос.у вас просто написано два раза специальный,вот я и подумала, вдруг надо)

Do they watch TV in the evening or in the morning?

They watch TV in the evening, don't they?

2 The boys are singing a nice song.

What are the boys singing?

Who is singing a nice song.?

Are the boys singing a nice song?

Are the boys or the girls singing a nice song?

The boys are singing a nice song, aren't they?

3 My mother has bought a tasty cake.

What has my mother bought?

Who has bought a tasty cake?

Has my mother bought a tasty cake?

Has my mother bought a tasty cake or an ice-cream?

My mother has bought a tasty cake, hasn't she?