when i was walking in the street i saw him quarr

问题描述:

when i was walking in the street i saw him quarr
ling with his brother 为什么是quarreling而不是quarrel呢

过去进行时:表示在过去某一时刻或某一段时间内发生或进行的动作或状态.
所以用V-ing形式求采纳么么哒