egin / start to do sth begin / start doing sth. 1) 谈及一项长期活动或开始一种习惯时,使用doing. How old were you when you first started playing the piano? 你几岁时开始弹钢琴? 2) begin,start用进行时时,后面动词用不定式to do I was beginning to get angry. 我开始生起气来. 3) 在attempt,intend,begin,start 后接know,understand,realize这类动词时,常用不定式to do. I begin to understand the truth. 我开始明白真相. 4) 物作主语时 It began to melt.
