I see what you are saying.

我知道你在说什么。

I don't understand what you are saying.

我听不懂你在说什么。

What you are saying is all nonsense and makes no sense.

你说的这些都是废话，没有任何意义。

What you are saying is all nonsense, with no basis at all.

你说的这些都是胡扯，没有任何根据。

What you are saying about Ishmael is not true.

你所论以实玛利的话是假的。

Eventually you will start believing what you are saying.

最终，你将开始相信你自己的话。

I would think about what you are saying rather than what I am gong to say next;

我会揣摩你话中的含意，而非揣摩自己的下文；

It is used when what you are saying is based on what you have heard, not on what you know is true and therefore fact.

当你听说了某件事而不是你自己确定这件事是真的的时候，你可以用“apparently”来表示这件事是事实。

Vivian: Excuse me, don't be fresh. I find what you are saying offensive.

维维安：对不起，别放肆无礼，我觉得你的说话带有冒犯性。

This is a complicated description and I understand most of what you are saying.

这是一个复杂的描述和我是理解你说的话的。