"We have a colorful flag."
Translation:Wij hebben een kleurrijke vlag.
Adjectives usually add an -E ending (a 'voiceless E' click to hear ) to the root word, except ... • Adjectives ending in -EN don't add E's. Many past participles and materials adjectives end in -EN. Verloren dagen click to hear ('lost days') • Words already ending in -E don't add an extra E. There are only a few words like this, I can only think of the colors oranje click to hear 2 3 - roze click to hear - mauve click to hear and beige click to hear 2. (The last three are pronounced as French words.) • Numbers don't change, no E's added to numbers: vier dagen click to hear - vijf minuten click to hear 2 (maybe numbers are not adjectives, strictly speaking) • 'Het' words (in singular) with the indefinite article een, 'n ("a") - geen ("no, zero") or no article at all don't add an -E to the adjective. (Poetic license allows occasional dropping of the adjective-E with 'het,' I think in root words of two or more syllables.)
i'm a year late, but 'wij' is emphasized and 'we' is unemphasized. it depends on the context- for example, if you're saying, "You don't have a colorful flag. WE have a colorful flag," you would use 'wij'. Duolingo just uses the two words interchangeably, however. it's a bit annoying :/