begin变 ing 形式要双写N么 还有 动词的ING形式都什么时候双写N?
问题描述：
begin变 ing 形式要双写N么 还有 动词的ING形式都什么时候双写N?
答
不用,现在分词,一般进行时,动名词做主语时还有时是固定句型Keep doinghave fun doingthink about doingwhat about doing do well in doingenjoy doing be good at doingfinish doing be busy doing practice doingas...