1. surprise, curiousity: “oh, you can speak Dutch? How nice!” Hidden meaning: it's surprising; unusual for foreigners to be interested in our language; but I really can't understand a word of what you're saying.
2. condescension: replying in English. Hidden meaning: ok, you've shown you can make yourself understood, now stop annoying us with your broken grammar and unusual vocabulary, let's switch back to English please!
3. tolerance: “ik vind je franse accent écht mooi!” Hidden meaning: we can communicate well, but remember that you're still a foreigner.

What's next?