She said to him:" Your school is big," => She said to him that........

Ka Be

$-$ She said to him that his school was big.

$+$ Cấu trúc câu gián tiếp tường thuật:

$(+))$ S + said to + S.O + (that) + S + V_lùi thì + O

$-$ Dịch: Cô ấy nói với anh ấy rằng trường học của anh ấy rất to.

$*$ Is (V): Là -> Was (V_c2)