If you could instantly learn a language, which one would you pick?

You find a genie in a bottle, but he's a special genie, he only deals in language wishes. So he will grant you instant fluency in any language of your choice, along with accent of your choice if applicable. You will be able to speak it, read it, write it, as if you were a native speaker.

It has to be a real language on Earth, no fake ones. No Klingon or Dwarvish or anything like that.

And before you complain that such-and-such language isn't in the poll keep in mind that I can only have 20 options. I googled to find the languages with the most number of speakers. But I also grouped some together, such as languages of India. I included an option for "Other" if the one you want isn't one of the poll options, but make sure you read over every option first because there are some "others" that are specific to a region of the world. Feel free to list it in the comments if you want.

No potato option. No giveaway. This is just to see what other people would choose because I'm curious.