What is the equivalent of "make sense" in Chinese? I am trying to explain the phrase "make sense" to my cousin, who is learning English. The dictionary suggests "有意义", but I believe that "有意义" is "meaningful" and that "make sense" should be "讲得通", "说得通", or "符合逻辑".

Consider the following situation:


  我一个北京的朋友居然在上中文入门这门课！
  
  One of my friends from Beijing is taking Chinese 101! [It doesn't make
  any sense!]


How do I translate the part in brackets? “这根本说不通？” Or maybe "居然" alone suffices?

Here is another example on Tatoeba.org. Is "你说的没有意义" "what you said is insignificant"? Since "有意义" is used pretty often in Chinese, I am wondering whether there is an English equivalent.
The most appropriate translation to make sense would probably be 有道理, which literally means has sense or reason.  For example:
你说的有道理
What you said is reasonable / What you said makes sense.

The phrase 说不通 would probably work, but it is not used frequently in Mainland China Mandarin (普通话) as 有道理 for the same context, if at all.
As for 符合逻辑, the phrase means the same thing as 有道理, but it is more verbose and academic.  It is like saying:
That is well reasoned. 
---as opposed to---
That makes sense.

As you can see the latter is what people use in daily conversations, while the former make you sound like some College Professor. ;-)
[It doesn't make any sense] would translate to 这没有道理。  Though in the context of your example, I think it sounds more natural in the Chinese context to say It is ridiculous (这太荒唐了） in response to the situation. Cultural differences in the way we think I suppose.