Faced with his accusations, I have nothing to say.

面对他的指责，我无话可说。

Jon:So, I have nothing to say.

乔恩：唉，我也没什么可说的。

Explanation means veiling so I have nothing to say.

解释意味着掩饰,所以我不会说什么.

I have nothing to say in reference to that incident.

关于那次事件,我无可奉告.

About that GH group, I have nothing to say about it, because it did nothing until now.

关于GH小组，我没有啥好说的，因为它到现在为止没干啥事情。

“I have nothing to say about this world, ” Teacher Fei said.

“对这个世界我已经无话可说。”范老师说。

No, thanks, don't bother with engraving, I have nothing to say to this bitch.

不，谢了，什么都不要刻，我对这个bitch无话可说。（这种没品的字也好意思刻上去，我还想刻别的送新男朋友呢……）