Hi v,
Thank you for contacting us. My name is Justin and I am a member of StackIdeas's Marketing team. I'll be assisting you with your post for today.
Once you've installed EasySocial's language pack, you need to install the same language pack for Joomla. Seeing that you've installed the Turkish language for EasySocial, you need to download and install the Turkish language for your Joomla. This can be done by navigating to your back end > Extension > Language Manager. From there, click on the checkbox for 'Turkish' and click 'Install'. Once you've installed it, navigate back to Language Manager and set the 'Turkish' language as default and you're all good.
Let us know if you need any further assistance pertaining to this issue.