Neither of them really means anything without some context - they are both slightly unusual, so they must come from an unusual source, and may perhaps have unusual meanings. If you are trying to write something, please provide the whole sentence, so we can see what you are trying to say.

"this tells that" = 直接說法. "this is a telling of" = 间接引语. 在什么情况去用, 與中文無異 :)

Hi Ethan, For the situation you are describing, the best solution would be "this is a tell-tale sign of psychological illness" (= it is indicative of psychological illness, it tells you that the person is likely to be psychologically ill). "This is telling of xyz" is used slightly differently. "50% of respondents indicated that they would not talk to a close relative about their issues. This is telling of our attitude as a society towards psychological problems" ( = this tells you something about our attitude). Note: "this is telling" not "a telling" - the latter sounds weird, unless you are talking about a tale, perhaps. "This tells ..." requires an indirect object like "you, us, ...": This tells you something about the issues he has. This tells you he has issues. Less formal than the rather clinical: this is indicative of his psychological issues or the more neutral this is a tell-tale sign of psychological issues. Hope I covered all the common options ;-) Update: Haha, and I just read Jimmy's comment and realize I did not. Didn't think of "this tells of" ;-)