我想从语法角度分析一下:You really shouldn't have fallen asleep during the lecture.
1.本本句子中,"shouldn't have done..."结构表示"本不应该做...(实际上已经做了)".
2."fall asleep"用在"shouldn't done..."结构中就成了"fallen asleep".
3.句子的意思是:你本不应该在听讲座的时候睡觉(事实上,听讲座时你是在睡觉).这是虚拟语气的一种用法.
睡着了~
fallen asleep 睡着了,睡觉
You really shouldn't have fallen asleep during the lecture. fallen asleep
你真的很不应该在讲座时睡着了
fallen 是fall的过去分词
fall asleep的意思是”入睡,懈怠”