This is the 3949th most frequent Polish word.
szwedzki
"Swedish" (relating to Sweden or its language).
In this sentence, 'szwedzki' describes the language being referred to explicitly.
Czy znasz szwedzki język?
Do you know the Swedish language?
Here, 'szwedzkie' is used as an adjective to describe the kind of cuisine served in the restaurant.
Ta restauracja podaje szwedzkie jedzenie.
This restaurant serves Swedish food.
In this context, 'szwedzkiego' refers to the Swedish language, with a grammatical case adjustment for the verb 'uczyć się'.