This is the 2nd most frequent Dutch word.
een
"Een" in Dutch means "a" or "an" in English.
Here, 'een' is used as the indefinite article before a singular noun, indicating an unspecified or general instance of the noun 'boek' (book).
Ik wil een boek lezen.
I want to read a book.
In this sentence, 'een' is used as a numeral meaning 'one,' specifying a single item out of multiple options.
Ze gaf me een van haar schilderijen.
She gave me one of her paintings.
In this instance, 'een' again functions as an indefinite article, emphasizing the non-specific nature of the noun 'probleem' (problem).