It’s strange that in many loanwords round vowels are in Turkish replaced with ü which I guess is probably a vowel unknown in most languages from which these words are borrowed: kültür, fakülte, üniversite, komünist, otobüs. I wonder if it was a try to make these words sound more Turkish or just a way to fill the place of a strange vowel with something familiar (which would be odd because Turkish has a good variety of vowels). This practice is usual with Arab loans also (hür, aleykümsalam, cümle, dünya, küre). When it comes to proper names, the notable thing is that not only round vowels then are replaced with ü: the names of two former Presidents of Egypt were spelled Cemal Abdülnasir and Hüsnü Mübarek in Turkish. Maybe it has to do with the vague marking of vowels in Arabic orthography.

I guess many of these odd appearances of ü can be explained with progressive assimilation which is a strong power in Turkish and actually the basis of vowel harmony. But examples like meşgul, -lü, petrol, -ü or malul, -ü very stubbornly object this rule. Is there a reason to stress their foreign origin or why don´t you just oppress these words under Turkish phonetical rules?

I believe your examples like kültür, fakülte, üniversite, otobüs etc are all French loans and that should be due to French influence.

Other examples meşgul, petrol, malül (I don´t have a dictionary but this is pronounced as malül) are because of the last "l" which is a back one and causes the next vowel to be an "ü" instead of "u".

Yes, it could be French influence. And of course French influence can be found in words which are not of French origin at all if there are any. How come I didn´t think of it?

But it´s a long way from l to ü. As long as from l to u to be exact. And what is a back l anyway? It´s not possible to change the place where l is pronounced very much. But it can be pronounced with the tip of the tongue or with a wider touch. Do you mean a dark or thick one? And if there was such a change why does it occur in so rare words? Can you ever see it in original Turkish words?

Say "olmak" and pay attention where you position your tongue for "l" it touches the teeth right.

Now say "ölmek" and pay attention where you position your tongue for "l" it doesn´t touch the teeth (it´s back).

Now when "l" is followed by "ü"  it´s always the second kind described above.

alkol - alkollü, alkolsüz

mentol - mentollü

gol (from Eng. goal) - golcü, gollü, golsüz

moral - moralce, moralli

metal - metalden, metalli

etc.

I admit there is a one millimetre difference... Maybe the l we are talking about is the one that I used to call the dark one.

Found something else. My grammar says without going too much into the phonetic detail that these words which choose their suffix variants against vowel harmony rules are all of French or Arabic origin. gol being one of them proves that it has been borrowed into Turkish through French, not straight from English.

What is funny about it is that while Turks understood the final l of Arabic and French words as being the same, the two of them did not agree. Goal is gon in Arabic.

I believe at least there is a 2 cm displacement when I say it.

I believe gol (goal) is an English word. Though they say the "l" in front we move it back (The same position when we say göl) so next wovel becomes an "ü" instead of an "u".

Golü gördün mü?

Golde kim hatalı?

Golcü futbolcu.

Two centimetres? What?

Seriously, I understood it now. As the pronounciation of l in these loanwords resembles that of original Turkish words with a preceeding round front vowel, the ö (which actually isn´t there) gives a false signal to the suffix vowel. I thought it was something that had been decided on paper but there was a real reason for it in language structure.

Phonetics is fascinating. I took a couple of introductory courses in the university but gave it up later. Those who continued say that it was mostly technical measuring of voices and the functioning of speak organs. But I can still draw a crosscut of human mouth without rising the pen from the paper and my eyes closed.