`1.` takes

`@` `DHNB` thì htđ " three morning a week" → S`+`V(s,es)`+`O...

`***` Nam ở đây là số ít → dùng `s`

`2.` is playing

`@` `DHNB` thì httd "at the moment" → S`+`tobe(is/am/are)`+`V-ing...

`***` He ở đây là số ít → dùng is

`3.` went

`@` `DHNB` thì qkđ "ago" → S`+`V(ed,c2)`+`O...

`4.` write

`@` Cấu trúc: S`+`should`+`V-bare...: nên làm gì đó

`giahan27511`

`1.` takes 

`-` HTĐ  (DHNB:  three mornings a week.):

S+ V(s/es)+O 

`2.` is playing 

`-` HTTD (DHNB: at the monent):

S+ is/am/are + V-ing +O 

`3.` didn't go

`-` QKĐ (DHNB: two days ago):

 V2/V-ed +O

`4.` write ( Cả câu: you should write to them today)

`-` should + V-inf +O : nên làm gì đó