Quote Originally Posted by Eugene-p
it's говорить о...

Informal/everyday: Ваши слова говорят о Вашей некомпетентности.
This phrase isn't everyday indeed)..it's formal, nevertheless.
In everyday speech it sounds like
"да ты вообще ни о чём"(too rude) or
"твои слова не в кассу"(not so rude, but unpleasant either) or
"ты не в теме" (most common expression, it' hard to offend smbd by that)))
yes, you got new participant of the forum, who likes slang phrases..that 3 expressions, that I gave, are in a use, indeed, and almost everybody in Moscow at least will understand you..mm, maybe some age limits..but it's true)