begin的过去分词是begun ，过去式是began。

begin：v.开始;启动;起始.

相关介绍

Could you go back to the beginning of the story?

你能不能回到故事的开头？

Work on the new bridge is due to begin in September.

新桥定于九月份动工。

She's been working there since the beginning of last summer.

她自从去年夏初起就一直在那里工作。