HTTD 

( + ) : S + be + V-ing

( - ) : S + be not + V-ing

( ?) : Be + S + V-ing ?

1 : My mother is watering some flowers in the garden

2 : My father is cooking lunch

3 : Marie is having dinner with her classmates in a restaurant 

4 : They are asking a man about the way to the bus stop

5 : My cousin is singing English songs

1. My mother is watering some flowers in the garden.

2.My father is cooking lunch.

3. Marie is having dinner with her classmates in a restaurant.

4. They are asking a man about the way to the bus stop

5. My cousin is singing an EngLish songs

Thì HTDT : S+to be+ Ving