Quote Originally Posted by Throbert McGee View Post
But it can get confusing if the antecedent is "dog" or "table" -- because in formal grammar, "that" is nearly always permissible, but "which" is sometimes incorrect. Mind you, even well-educated English speakers often ignore these traditional grammar rules, and use "which" and "that" interchangeably, because we can't remember when "which" is allowed and when "which" is not allowed. (If you want a more detailed explanation of when to use "which" and when to use "that," feel free to ask. But the short and simple answer is: When in doubt, use "that".)
It's the other way round in Russian. When in doubt, use "который". "Кто"/"что" can be permissible but stylistically incorrect.