“to have been doing” 是英语中一种不定式的完成进行时形式,由以下结构组成:
to + have + been + 动词-ing 形式
它通常用于表达某个动作从过去某一时间开始,一直持续到另一个过去或现在的时刻,并可能仍在继续。
to have been + V-ing(如:to have been studying)not to have been + V-ing(如:not to have been working)She seems to have been crying.(她看起来一直在哭。)He is said to have been living abroad for years.(据说他已经在国外住了好几年。)
He was tired to have been running all morning.(他因为一早上都在跑步而感到疲惫。)
They claimed to have been waiting for hours.(他们声称已经等了好几个小时。)
to be doing:表示正在进行的动作(一般现在/将来)。to have done:表示已完成的动作(完成时)。to have been doing:强调动作的持续性和未完成性(完成进行时)。to have been doing 和 to be doing。前者强调“从过去持续到现在”,后者只是“正在做”。