To illustrate the point, metalanguage is the language "within the language".

http://englishlive.ef.com/blog/metalanguage-will-help-english/

That is, the language can be learned by other "borrowing" information from other experiences, for example terms and ideas/notions from soccer/sports, or from other fields that helps people to make a "representation" to explain things and to express themselves.

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Metalearning - the process of learning to learn.

Metalearning skill - the are skills that improve your ability to learn other skills.