Helen (borrowed) my book the other day,(saying) that she wou

Helen (borrowed) my book the other day,(saying) that she would return it soon.
Helen (borrowed) my book the other day,(saying) that she would return it soon.
请问这个句子是什么时态?
请问为什么要用saying?是表示伴随状况吗?表示伴随状况一定用现在分词吗?
请问为什么borrow要用过去式?是因为 the other day
the other day 意思是什么?是指第二天吗?
为什么老师说 the other day 用于过去进行时?
不能用于其他时态吗?