Whenever you have "the adjective noun" you must use the plural form of the adjective.
OOHHH. Somehow I didn't pick up on that. I was confused for so long. Mange tak
The + an adjective + a noun. The red ball. The blue water. The beautiful woman. Instead of simply adding -en or -et to the end of the noun for "the" you must use den or det, then use the adjective in its plural form, and then use the noun.
How is it weird? The 'v' is pronounced like a 'u' as is common in Danish, if that's what you're talking about.
But not everywhere. In March 2016 I was in Vestjylland and the people there pronounced the "v" similar to an "f". For the number 7 (syv) they said "syf" and not "sy-u".