Quote Originally Posted by Medved View Post
Okay, let's blame it on my pickiness.
Similarly to English, it's not usual to ask "can you speak English?" we just ask "Do you speak English?" Of course there are contexts where you might say "you can speak English," - i.e., giving someone permission to speak English - this usage would usually be similar to Russian ты можешь говорить по-русский

But- in English "can" has many different uses, including ability to do something and permission/ possibility. In Russian, мочь is not used to describe ability to do something, they say уметь. for example, я не умею плавать means "I can't swim" (I don't know how to). я не могу плавать is different, it could mean something like I'm physically prevented from swimming, or I don't have permission.

So if you want to say "I can speak Russian" in the sense of having the ability to speak it, it will be я умею говорить по-русски