`1` `(-)` She is not a doctor 

`(?)` Is she a doctor ? 

`2` `(-)` My brother does not play football 

`(?)` Does your brother play football ? 

`3` `(-)` My younger sister does not have a doll 

`(?)` Does your younger sister have a doll ? 

`=>` Thì hiện tại đơn : 

`-` Với be : 

`(+)` S + is / are / am + O 

`(-)` S + is / are / am + not + O 

`(?)` Is / are / am + S + O ? 

`-` Với Verb : 

`(+)` S + V ( s - es ) + O 

`(-)` S + don't / doesn't + V + O 

`(?)` Does / Do + S + V + O ? 

`1` 

`(-)` She isn't a doctor 

`->` Cấu trúc : S + be + not + (a/an) + N/adj

`(  ?  )` Is she a doctor ? 

`->` Cấu trúc : Be(am/is/are) + S + (a/an) + N/adj ?

`2` 

`(-)` My brother doesn't play football 

`->` Cấu trúc : S + do/does + not + V-inf

`(  ?  )` Does your brother play football ? 

`->` Cấu trúc : Do/does + S + V-inf ?

`3` 

`(-)` My younger sister doesn't have a doll 

`->` Cấu trúc : S + do/does + not + V-inf

`(  ?  )` Does your younger sister have a doll ? 

`->` Cấu trúc : Do/does + S + V-inf ?