实用口语：can't put my finger on it

Can’t put my finger on it 无法准确确定或解释某个事物或情况

(没有办法具体指出)

e.g. Something about this place feels weird, but I can't put my finger on it. 这个地方有些奇怪，但我说不清楚是什么。

e.g. I'm not sure why, but I just have a strange feeling today. Can't put my finger on it. 我不确定为什么，但今天我有一种奇怪的感觉，说不清楚是什么。

后面也可以接具体的事情can't put my finger on + 具体事情:

e.g. You look familiar, but I can't put my finger on where I saw you before. 你看起来很熟悉, 但是我也没法具体说出来以前在哪里见过你.