This is the 787th most frequent Swedish word.
engelska
The Swedish word "engelska" means "English" (the language).
Here, 'engelska' is used as an uncountable noun denoting the English language.
Jag talar engelska med min vän.
I speak English with my friend.
'Engelska' is an adjective in this sentence describing the word 'culture' to mean related to England or its traditions.
Han läser en bok om den engelska kulturen.
He is reading a book about the English culture.
Here, 'Engelska' is a proper noun referring to the subject of the English language, taught in school.