@JeremyECrawford Can non Druids learn Druidic? Also can non Rouges lean Thieves Cant? Not seeing that says they can't learn it.
— Barry Zanone (@BarryZanone) February 16, 2017
Languages—see "Languages" (PH, 123) for how to learn more of them, including the possibility of Thieves' Cant or Druidic. #DnD https://t.co/zg09M51p2u
— Jeremy Crawford (@JeremyECrawford) February 16, 2017
Why doesn’t he just say Yes.
For posterity: The answer isn’t ‘yes’. The answer is ‘ask your DM’.
“With your DM’s permission, you can instead choose a language from the Exotic Languages table or a secret language, such as thieves’ cant or the tongue of druids.”