察觉出

How did you spot those fifties were counterfeited?

你怎样察觉50元面值的纸币是伪造的?

I detected a faint note of weariness in his voice.

我从他的声音中察觉一丝倦意。

I can detect signs of improvement in your thinking.

我可以察觉你思考题方面的进步。

I soon discerned that the man was lying.

我很快便察觉这个人是在撒谎。