Isn´t there a Turkish Language Expert?? Yes it is weird for us discussing this Merih.

Your explanations sounds right as well, but still my explanation has value to be true.

Gelmenden önce is a usage yes. Here me makes the verb noun, true.

But gelmezden önce is also used. I am very sure. And it is made of negative form.

So which one is right?

Ah haaa! I must find a Turkish teacher to be sure of it

I truely believe it _-me/-ma can not be the neagtive suffix.. it must be tutrnin verb into a noun..Yes I thought the same thing but there is something negative in it. I got curious and I checked its old Turkish form (which is -meti -medi medin -metin from Grammer of Old Turkish A. Von Gabain) and I think older forms seem clear enough to me that there is -me- negative verb suffix there. probably "before" and "without" meaning were different in old times and they are now the same form (sound changes).

gitmeden beni gör = come see me before you go

gidip görmeden bilemezsin = you cannot know it without going there and seeing

The second thing is you can use "gelmezden önce" form, meaning adding -mez suffix. It is not commonly used, that´s why it sounds a bit weird. to me also

Third thing, I have been thinking that i have definitely heard something like - gelmenden önce - meaning before your coming... or - in a sentence like:

Bu köye elektriðin gelmesinden önce insanlar gaz lambasi yakarlardý..

But in this case its noun form of the verb + possesive suffix and it is not "zarffiil"

I don´t know know what you call it, but it sounds pretty correct to me.

Well, though it sounds a bit negative, it is not.. I believe.. but I don´t know how to explain it.. and i think, like anka has mentioned: gidip gelmeden (once) bilemezsin.. here once has fallen off.. I think..

By the way your reserach is of course correct:

checked its old Turkish form (which is -meti -medi medin -metin from Grammer of Old Turkish A. Von Gabain) and I think older forms seem clear enough to me that there is -me- negative verb suffix there.

if you noticed the verb suffixes are at the end.

On the other hand if you were to use gelmeden in the following sentence:

gelmeden yapamazsin, gelerek yapabilirsin...

then it is negative..

but you can´t use the same logic with önce.. that´s why it is not negative.. again i believe...

gelmeden once - gelden once?????

I am still confused but si++, your study of Turkish is quite admirable!! I am impressed with its perfect structure, so it´s an hobby for me to study it.

Hi Anka, nice to meet you.. i did not say gelmezden once is wrong.. i said it is used in this way as well as in the other way.. but I checked the internet... -mez here is not a negative suffix, it is :Objection of course -mez is a negative suffix and it´s not "zarffiil" either (It´s a "sýfatffil" as far as I know). Yeah only in dual usage like "gelir gelmez" but otherwise it´s a negative "sýfatfiil".

3. ZARF FÝÝL EKÝ (ULAÇ, BAÐ – EYLEM):

Fiil kök ve gövdelerinin üzerine –ýnca, - dýkça, - dýðýnda, -ken , -r… -mez, -alý, -erek, -madan, -meksizin, -a…-a, -ýp

ekleri getirilerek oluþturulur. Zarf- fiil ekleri temel cümlenin zarf tümleci olurlar.