otherwise he would try to borrow it from me.

　　Tom: William has asked me for a loan of five pounds. Should I be doing right in lending it to him?
　　　Jack: Certainly.
　　　Tom: And why?
　　　Jack: Because otherwise he would try to borrow it from me.

　　　汤姆：威廉向我借五英镑。我该不该借给他？
　　　杰克：当然应该了。
　　　汤姆：为什么？
　　　杰克：否则他就该跟我借了。