YOU SAID:
why did they not read to the horse
INTO JAPANESE
なぜ彼らは馬に読まなかったのですか
BACK INTO ENGLISH
Why didn't they read on horses
INTO JAPANESE
なぜ彼らは馬で読まなかったのですか
BACK INTO ENGLISH
Why didn't they read on horseback
INTO JAPANESE
なぜ彼らは馬に乗って読まなかったのですか
BACK INTO ENGLISH
Why didn't they read on horseback
That didn't even make that much sense in English.