Turkey is a country that geographically borders both Europe and Asia. Culturally, most people consider Turkey a Middle-Eastern country, and there certainly is no doubt that Turkish culture has similarities with the culture of many of the other countries of the region, such as Arabic-speaking Syria, Iraq, Palestine, and Jordan.
Turkey does indeed have a great deal of shared history with, not only Middle-Eastern countries, but also some European countries such as Greece and Bulgaria, and even North African countries like Algeria. This common history is mostly due to the historic reign of the Ottoman Empire, where Turks ruled a large part of the Middle-East, Asia, and even Europe.
Many people see the similarity of Turkish culture and that of its Arabic neighbors, however, and assume that they must speak the same language. This is very far from the truth.
Turkish is not a form of Arabic. It not even remotely related to Arabic, but belongs to a separate language family, Turkic, which has absolutely nothing to do with Arabic, which is a Semitic or Afro-Asiatic language much closer to Hebrew. The Turkish language has, however, borrowed quite a lot of vocabulary from Arabic and until the beginning of the 20th century, it was written in the Arabic script.
Interestingly, however, Arabic is spoken by a minority of people in Southern Turkey.
The Turkish Language's Relationship With Arabic
The Turkish language actually didn't originally come from Anatolia, the region of modern-day Turkey, but rather from Northern China or Mongolia where the first Turkic languages were spoken some 3000 years ago. The Turkic people who spoke the language gradually turned into a powerful nation which, in time, invaded more territory to the west.
Around the 11th century, the Turkic people became Muslims. The Turks had been in contact with the Arabs as well as the Persians for a long time, but only superficially as trade-partners.
With the adoption of the Muslim religion, the sacred scriptures of Islam followed, and the Turks started using the Arabic writing system, not only for writing the Quran but also for writing the Turkish language. With religious ties to the Arab Muslims, a great cultural exchange began and the Turks adopted many Arabic, but also Persian loan-words into their language.
In time, the Turks grew even more influential and after a few centuries, they even surpassed the Arabs and began ruling most of the countries that were part of the Muslim world. This is the period of the Ottoman Empire, which spanned from the 13th century to the end of the first world war.
During Ottoman times, the Turkish language underwent significant changes. Not only in terms of using the Arabic script and Arabic and Persian loan-words, but even grammatical structures in the Turkish language were changed.
By the beginning of the 20th century, the fall of the Ottoman Empire meant that the Turks had to redefine themselves, and a new form of Turkish nationalism arose.
This was a period where many language reforms were carried out. Many Persian and Arabic loan-words were replaced with either historical Turkic words or words of European origin. The Arabic script, which had never been very well suited for the Turkish language, was replaced with a specialized version of the Latin script which was a much better fit for the variety of Turkish phonology.
So Is Turkish A Form Of Arabic?
The answer to the question is a loud and resounding NO.
Turkish belongs to a completely different language family than Arabic and is as different from Arabic as English is from Chinese.
... In principle...
The Turkish language does have quite a few Arabic influences, however, namely in terms of loan-words. Historically there were a lot more Arabic influences visible in the Turkish languages, but many of these were removed when the language-reforms at the beginning of the 20th century were carried out.
While Turkey shares some cultural themes with (some) Arabic countries, such as elements of the cuisine, the oral tradition, and elements of the musical style, the two languages are really very different.