One such scene took place, in which a dialogue took place between about five people, one of whom was using French. He said 'We have to know who our enemy is', and a Flemish speaker replied 'enemIES', stressing the fact that there are more than one single enemy. This is contrastive stress, and is a nifty way of indicating that you're contrasting something you've said with something the other person either said or implied. The contrast can be lexical/semantic: I want BEANS (not cheese), or it can be grammatical, as you can see here, where singular is contrasted with plural. Normally you need to contrast two things that are similar in some way, like two nouns/foodstuffs/potato fillings.
What's special about this is that the two languages do plural in different ways. French adds an -s in the written language, going from ennemi to ennemis. But in fact, in speech, you won't usually hear that -s, and the only thing to tell you the difference is the 'determiner', an article, demonstrative, etc. In this case it was 'our', which in French is notre for singular and nos for plural. I didn't catch the exact word in Flemish but in Dutch it's vijand for 'enemy' and the plural is marked with an -en: vijanden. The possessive determiner stays the same, and in any case the Flemish speaker didn't repeat 'our'. So we had this:
A: (We have to know who is) notre ennemi.
B: vijandEN.The Flemish speaker contrasted a possessive determiner with a totally different morphosyntactic category, a plural inflection, because he was contrasting the feature [number], which is encoded on the determiner in French and the noun suffix in Flemish.