A proverb or idiom in English for people who pick up a new language very quickly

The English phrase "quick study" is not limited to linguistic prowess, but it certainly applies.

n.

One who is able to memorize something easily and quickly,

or is able to understand and deal with something easily and successfully.

"Janice is such a quick study that we can call her to solve any problem in the company."

Sponge is a recent colloquial synonym, and is listed as a synonym for "quick study". Although that definition is not listed in any of the dictionaries I currently use, I have used the term in that fashion myself:

Joey is a sponge for baseball statistics; you'll be hard pressed to stump him.

It would be more recognizable in the simile

She has a mind like a sponge!

I like the word picture of "spending the night with the chickens!" If we can't find a preexisting proverb or idiom, I'd like to generate one today:

He soaks up language like a sponge!

Specifically for languages, an idiom one might use is to say the person had an ear for languages, which implies being a quick study at the spoken form of any language.

The language we learn first, best and most quickly is often referred to as our

mother tongue:

NOUN

The language which a person has grown up speaking from early childhood:

"English is my mother tongue, but I have wrapped my heart in a few other languages too."

It's not a preexisting proverb, but building on that word picture of mother tongue, we could imply linguistic dexterity with a question:

Did his mother give him that tongue too?

or

How/When did his mother give him that tongue?

or

Whose mother gave him that tongue?

He took to Swahili like a duck to water.