Which regions became major contact areas for Turkic languages?

The historical diffusion of Turkic-speaking groups from the Eurasian steppes into diverse territories led to significant linguistic interaction and the development of major contact areas. According to historical records, the Oxus region and Crimea specifically emerged as major contact areas for Turkic languages.1

These contact zones were shaped by the movement of Turkic peoples into regions already inhabited by other linguistic groups, leading to extensive mixing and the leveling of various Turkic varieties. Furthermore, the prolonged geographic proximity of Turkic languages to other cultures facilitated significant linguistic influence:1

• Central Asia: This region has served as a primary site of interaction, particularly between Turkic and Iranian languages, resulting in profound mutual influence between Uzbek and Tajik dialects.2
• Southern Siberia: This area has experienced particularly strong interaction with the Mongolian language.2
• Diverse Influences: Throughout their expansion, Turkic languages have adopted loanwords from numerous sources, including Indo-Iranian, Chinese, Arabic, Persian, Slavic, and Uralic languages, as well as European vocabulary in more modern contexts.2