father made a promise that if I passed the exam he would buy me a computer.

问题描述:

father made a promise that if I passed the exam he would buy me a computer.
已经有if 做引导词了.前面还能再加that

that 不可以省略,因为that引导的是promise的同位语从句,在同位语从句中,if引导条件状语从句,而真正的主句是 he would buy me a computer.