Have you heard the song ____( sing) in Japanese before?

Have you heard the song (singing) in Japanese before?
你听过这首用日语唱的歌吗？
singing现在分词作后置定语修饰song

Though he said he (would explain) the rules to us, he never did.
虽然他说过他会给我们解释这些规则，但是他从来没有做到。
整个句子是过去时，而explain需要表示将来，所以用过去将来时

He told me about his (not passing)the history test.
他跟我说了他为什么没通过这个历史考试。
his后边应该跟名次形式，所以将pass转换为动名词

After finishing the job, they expected (to be paid).
完成这个工作后，他们想要得到报酬。
按照句意即可

Have you heard the song sung( sing) in Japanese before? [歌不会自己唱，而是被唱所以用被动语态。]

Though he said he would explain(explain) the rules to us ,he never did.[根据后面一句，表明他还没有解释，用过去将来时。]
He told me about his not passing(not pass) the history test.[about是介词，后面的动词要加-ing,否定式直接在前面加not]
After finishing the job ,they expected to be paid(pay). [expect to do sth.（期望做某事），根据题意，表示被动用被动语态。]

Have you heard the song _sung___( sing) in Japanese before?
Though he said he would explain____(explain) the rules to us ,