Translation:He speaks Italian, Danish, English and Chinese.
Actually you can learn Chinese here but its intentionally made for Chinese people to learn Spanish.
https://www.google.be/url?sa=t&rct=j&q=&esrc=s&source=web&cd=10&cad=rja&uact=8&ved=0CEoQFjAJ&url=http%3A%2F%2Fwww.grammarly.com%2Fblog%2F2015%2Fwhat-is-the-oxford-comma-and-why-do-people-care-so-much-about-it%2F&ei=-yeJVaywNIroUsXLgagN&usg=AFQjCNH3dMq6Dx2xFUqQilS3u3nVEDffew&sig2=sDsgHd4n9xtPWe0Y4eP8SA&bvm=bv.96339352,d.d24 He speaks Italian, Danish, English, and Chinese.
Having checked this website, it turns out that it's the last comma in a list. We were always told at school not to add a comma before the last item in a list.
What's wrong with: "He talks Italian, Danish, English and Chinese." (english is not my native language, it's dutch)
"He talks" sounds a bit incorrect (more uneducated); it is better to say "He/she speaks" when you are referring to languages a person has knowledge of. I would say using "talk" is more about the action (the physical conversation being had between people).
Would be like saying "Hij praat Nederlands" (I'll just hope that sentence sounds ridiculous in Dutch, I'm really not too well-versed in that language)
Ask the duck - he knows!