Correctly pronouncing a language to the level that it's indistinguishable from a native is one of the biggest (if not the biggest) hurdles to learning a new language. It seems easy but I would wager that exclusively germanic-language speaking people are not able to properly pronounce, say, Chernobyl. (If you watched Brooklyn 99, their running joke with Nikolaj is very accurate)

To one's own ear, filtered through their own perception of the sounds they know and put together to speak the words, it sounds OK. But do try to learn to order a coffee in the local language when you go somewhere and see if they respond in English or not. This may vary between people and their background - say a Swede might pull it off in Norway. But send the Swede to Slovakia and it might be a bit more difficult. Look up the pronounciation for Gulden Draak (spelling?) if you're not Dutch and have some fun with that.

Edit: this is also why shibboleths are a thing