1.Could write => could + V

2.Couldn't attend =>could + V

3.Couldn't get =>could + V

4.Couldn't arrive =>could + V

5.Could speak =>could + V

6.Couldn't understand =>could + V

7.Could play => could + V

8.Could open => could + V

9.Could play => could + V

10.Couldn't find => could + V

$\text{@su}$

`1`, could write

`2`, couldn't attend 

`3`, couldn't get

`4`, couldn't arrive (dựa vào ngữ cảnh để làm)

`5`, could speak (dựa vào ngữ cảnh để làm)

`6`, couldn't understand

`7`, could play

`8`, couldn't open

`9`, couldn't play

`10`, couldn't find (thực ra could not cũng được nhưng phải cách ra)

Bonus: Modal verbs "could" (quá khứ của can)

S + could + (not) + Vbare + ...

$\text{#BTS}$