i don´t worry about this kind of stuff, the nitty gritties of grammar - just learn the lingo the way kids do, the generalizations will crystalize out naturally the more simple words and frases you learn. The eggheads have actually measured it and found out that your are better off knowing more words and simple expressions than having perfect grammar, that´s for getting around on the daily basis. ... Hoşça kal !  ^_^