He told the new pupil what to do first.

$⇒$ The new pupil was told by him what to do first.

$Form:$ Câu bị động ở thì quá khứ đơn:

S + V2/ed + O

$⇒$ S + was/were + V2/ed + (by O).

$Example:$ She cooked the meal. $⇒$ The meal was cooked by her.

$@haanx2$

$@Mayumi$

`=>` Đáp án: The new pupil was told by him what to do first.

`+` Cấu trúc câu bị động - thì QKĐ
`(+)` Khẳng định: S + was/were + PII + (BY  O)

`-` The new pupil là chủ ngữ số ít `->` tobe là was