What do you do when neither your character nor you speak a language?

The Twirl and Swirl of Letters

I’m working on my not-so-epic-yet WWII story.

I’ll divulge a small portion of it (as I haven’t done too much research/plotting yet).

My main character, Jim, is an RAF pilot who gets gunned down over Holland. He doesn’t speak Dutch.

Problem is, neither do I.

I want to convey the lack of understanding between he and his “captors.” My initial thought would be that they would speak in Dutch, and I wouldn’t provide a translation, so neither the reader nor Jim understands.