`8.` haven't ridden

`\text{→HTHT: (-) S + haven't/hasn't + VPII + ...}`

$\textit{→nhận bik: for}$

`9.` have never met

`\text{→HTHT: (+) S + have/has + VPII + ...}`

$\textit{→nhận bik: never}$

`10.` left `-` rang

`\text{→QKĐ: S + Ved/VPI + ...}`

$\textit{→nhận bik: last night}$

`11.`  have you washed

`\text{→HTHT: (?) Have/Has + S + VPII + ...?}`

`8.` haven’t riden

`-` Thì HTHT – for years

`-` Form: S + have/has + not + VpII + ...

`9.` have never met

`-` Thì HTHT – never

`-` Form: S + have/has + not (have/has + never) + VpII + ...

`10.` left – rang

`-` thì QKD – last night

`-` Form: S + V2/V-ed + ...

`11.` Have you washed

`-` Form: S + have/has + VpII + ...