I recently started using a VPN and I've felt more comfortable browsing the Internet. My VPN allows me to select another country through which my traffic is routed to make it appear I'm located in that particular country. "What's my IP" and similar services show my IP address located in that country as expected.
Search engines, however, are apparently not fooled. As I go to Google, for example, the front page is in my native language and it says my true country of origin at the bottom of the page. I was aware that this happens, as a VPN is not truly a means to make myself anonymous, and companies like Google can track my true location (I assume they do this for example by looking at the country specific top-level domain of the sites I visit?).
But what puzzles me though, is that other search engines, such as DuckDuckGo, which promise not to track their users in anyway, can also see my true country of origin. The front page of DDG also appears in my native language (not English).
So how is it that DDG and other "non-tracking" services see my true location without "tracking" me? Even when my IP address is located somewhere else, what gives my location away in such an obvious way that DDG can still claim not to track me?