Please tell the Turks about this too! :D I know that in theory and in standard language it is like this, but here in İstanbul I hear people using yok all the time. In fact, I find myself absorbing this, having troubles with using hayır. Can any one tell me more about the use of the two words in colloquial language?
From what I have heard, "yok" was the original word in Turkish for "no", but at some point, it was felt to be too blunt and was replaced by "hayır" from an Arabic word meaning something like "good" - I think at first there was a two-word expression meaning something along the lines of "I'm afraid not" but it got worn down to just "hayır".
So it could just be that "yok" survived in daily speech among some Turks - or that it was independently revived.
Maybe you are right because we also have "nakheir", (na(no)+khayr) which is used when someone want to emphasize on a statement being wrong, For example:
"Are you a girl?" (to a obviously baby boy for example as kidding, stuff like that...)
"Nakheir! I am a guy." (The boy answers)
Here What TDK says: Ex: "Geldiler mi? -Yok, daha gelmediler."
"Did they come? - No they didn't come yet."
It is because Istanbul Turkish, which is the standard, has dropped this sound "kh". So any of three "h"s of arabic or the two from persian has boiled down into a single "h". But you hear this sound "kh" (or "x" as it is spelled in Azeri) in the central and eastern anatolian dialects.
Well, the theory says that Proto-Japanese and Proto-Turkic are related. Obviously a lot of time has passed, so you can’t really see the relation anymore unless you know what to look for. Theory has it that Turkish -lar and Japanese -ra (～ら・等, as in bokura 僕等) are related, for instance.
The theory that links Turkish and Japanese is the Altaic theory, for which I guess Thomas Gamkrelidze and Vyacheslav Ivanov would be your guys. It is controversial because it is enough further back than Proto-Indo-European that it is much harder to reconstruct, especially with no ancient texts. But not as controversial as the same pair's Nostratic theory, which links Altaic and PIE! :-)
In persian kheyr means: no. (In polite way) For example: no, i'm not studient. In persian says: keyr, Man danesh amooz nistam.
We can also say "no" instead if "kheyr". But kheyr is more formal.
In arabic khayr means: better. For example: when i wanna say "better than gold" i say: khayr men zahab. (خیر من الذهب)
In turkish. Hayir" means "no". " Yok" has a meaning that goes in the direction of "nothing" or "non-existent" although it is sometimes used as "no" and degil is more like not.
I think it's called "ı", and the dotted one is called "i".
Just like English calls its vowels by the sounds they make (specifically, the ones they make when "long").
I don't think they're felt to be variants of the same letter any more than English calls the letter "b" "upside-down p", even though the sounds are related and the shapes are, too.
To quote myself "The letter /r/ in Turkish is a pretty mysterious sound. When between vowels, it is like the Spanish /r/. When before a consonant or at the beginning of a word, it sounds like an English /r/. When at the end of a word, it becomes devoiced and sounds like an "sh" to an English speaker, but I promise you, it is not."
You are not totally wrong. Your tongue should be placed a little more forward for pronouncing "r". But they are distinct sounds. Otherwise we cannot distinguish between words such as "gelir" and "geliş", which are both very common.
There is also a distiction between male and female accents for "r", which should be taken seriously :).
How do you know when to use the letter (ı) and (i) also the same for ö and o , ü and u
It's like asking how to know when to use l in English and when t -- or when to use p q d b.
Those are simply completely different letters; you learn the spelling together with a word.
So you learn that "pot" and "dot" and "bot" mean different things, or "lick" and "tick", or that "spin" is a word but "sqin, sbin, sdin" are not words: that word has to have a "p" in it.
Similarly, don't think of ö as a "funny o". It's a separate letter.
When you learn a word, learn whether it has o or ö in it just like how you would learn whether it has l (no line through the letter) or t (with line) in it.