For the speakers of European languages it is usually quite difficult to learn to pronounce correctly some of the sounds of Arabic. Turkish does not have any sounds hard to pronounce for Europeans.

The Indo-European languages and the Afro-Asiatic, including the Semitic languages like Arabic, are distinguished from most languages of the world by having much more irregular grammars, of the kind that was traditionally named "inflected".

Amazingly, while the more irregular grammars of the "inflected" languages are better seen as a bug and not as a feature, in the past the European scholars believed that such grammars are a sign of superiority of the Indo-European and Semitic languages, even if it is much easier to argue in favor of an opposite point of view.

In conclusion, I believe that for a speaker of European languages it is much easier to learn Turkish, due to easier pronunciation and more regular grammar.

Nevertheless, when there is no special reason for learning either of the languages, Modern Standard Arabic or Classical Arabic are more interesting languages from a historical point of view, enabling the understanding of many facts about the old Arabic literature or pertaining to the related Semitic languages that have been very important in the Ancient World or about the origins of the Greek and Latin alphabets (Standard Arabic has a conservative phonology and it still distinguishes most of the sounds for which the oldest Semitic alphabet has been created, which has later evolved into the simplified Phoenician alphabet, from which the Greek, Aramaic and Hebrew alphabets have been derived).

It would probably be fun to read some original mathematical texts in arabic if you could. I would say that since modern turkish didn't come into being until the founding of the republic, you really do lose the historical context. I would love to learn ottoman turkish one day...

Actually there is no such thing as Ottoman Turkish, it is still Turkish with heavily borrowed phrases. It is not a distinct language. You won’t have any hard time understanding the spoken Turkish in Anatolia of that time. So called Ottoman Turkish was mostly limited to the government and literature use. Here is a recording of “Ottoman Turkish” from that time.

https://m.youtube.com/watch?v=fmNl4gcufBU&pp=ygU0RXNraSBrYXl...

I'm too out of practice to really engage at this level. But actually, I meant I would like to learn the Ottoman Turkish of government and literature. I obviously can't go back in time and converse with the Anatolian turks and if I could, I might prefer to also have some Greek and Armenian in my toolbox...

I don't know any Arabic unfortunately. They are completely different language families with only slight overlap in vocabulary, but beyond that I can't make a comparison. I would say it probably depends on what your language learning goals are, but turkish is super fun to learn and speak, and its super fun to travel in turkey or just to hang out in istanbul. You might also surprise yourself speaking turkish in China one day with some Xinjiang people as well :D

To add, knowledge of Turkish will also make it easier to converse in Azerbaijan, Uzbekistan, Turkmenistan and a bunch of other countries in the region.

To add to that, I learnt to basic-speak the now extinct language of Chagatai, because I know Turkish.

Turkish is also mutually intelligible with Uzbek and Kazakh - it's basically like English and Dutch.

Edit:- Learning Chagatai practically let's you speak Kazakh and Uzbek partway. Tried it in both countries, might work in other places like Kyrgyzstan and Turkmenistan too. :)

Also many Iranians speak 'Turk' and understand Turkish from watching Turkish telenovelas on satellite TV.

More than half of the Iranian population belong to an ethnic minority, and the biggest by far is the Turkish speaking one, the Azeri - it's something like 1/3 of the population as far as I remember. I don't know if non-Azeri learn Turkish from TV, but for a lot of Iranians it's simply their first language.

Good point! Although, what they call 'Turk' is actually Azeri :) (Part of the historical Azerbaijan is in Iran.)

How very interesting, I understand Turkish and Farsi are totally unrelated (Turkic and Indo-European language families).

I took three years of Arabic as an undergrad, it's an interesting language to study, but needing to learn the alphabet will make it more difficult than Turkish, I would say. Which might be fine if you're looking for a challenge!

All other things being equal, I didn't feel up to the task of learning a language that regularly omits all vowels in written form. But man, that calligraphy...