having done 是非谓语动词中现在分词的完成式.与现在分词一般式doing 相比,doing表示的动作或状态往往与句子谓语动词表示的动作或状态同时发生,而having done 强调在谓语动词之前发生.having done 通常在句中作状语,表示句子主语发生的动作或存在的状态,与主语是主动关系.例句:①Having worked there for 30 years, Haydn moved to London.②Having promised to stay with my mother, I didn’t accept the invitation to the party.(2) having done 作状语,可以变成相应的完成时的状语从句.比如上两句可分别变为:①After he had worked there for 30 years, Haydn moved to London.②Because I had promised to stay with my mother, I didn’t accept the invitation to the party.(3) having done 的被动式为:having been done, 与句子主语之间是被动关系.例句:Having been discussed for many times, the problem remained unsolved.该句同样可变为:Although it had been discussed for many times, the problem remained unsolved
