`1.` Her new car has been washed for an hour.

`->` Her new car là N số ít, dùng Has

`->` Bị động HTHT (`+`) : S + have/has + been PII (by O)

`2.` Has this language been learnt for 10 years?

`->` Bị động HTHT ( `?` ) : Have/has + S + been PII (by O)?

`->` This language là N số ít, dùng Has

`1.` The new car has been washed by Lan for `1` hour.

`-` The new car `->` Số ít: S + has been PII 

`2.` Has this language been learned by you for `10` years? 

`-` This language `->` Số ít: Has + S + been PII

`-` Bị động HTHT: 

`(+)` S + have/has + been + PII + (by O)

`(?)` Have/Has + S + been + PII + (by O)?