How Fast Can Genius Creatures Learn Language

[Volt Cruelerz]

Suppose you have a newly hatched dragon on your hands. In your world, dragons are real, can learn to speak, and have eidetic memories. How long would it actually take the creature to pick up language enough to converse with you, at least on a basic level?

Assume that dragons are not wired to automatically know language out of the gate, but do have the brain structures to learn them, much like humans do.

 

[Benwise]

Daniel Tammet supposedly learned conversational Icelandic in a week, and a pair of twins from Manchester apparently made crazy progress learning Turkish in the same timeframe.

Do note that these examples involve people that already have experience with learning languages making an concentrated effort, instead of starting literally everything from scratch. Also these facts were learned from the bare basics of research, so do take them with a grain of salt.