began是begin的过去式。begin后要用动词不定式to do. She began to explain her plan of action to the group. 她开始向小组讲解她的行动计划。 He began to...
begin to do 后面接的sth（某事），表示开始做某事; begin to do sth里面的动作是突发的，不是习惯 The train began to pick up speed. 火车开始加速。 She ...
