[shautvast]

the -en ending indicates the infinitive in Dutch

[SushiHippie]

Same for german (I think).

We also have nix/nichts which means nothing. And "nichtsen" would somewhat make sense in german, at least I think most people would understand it.

[brnt]

-sen also can be son-of (e.g. Jansen), it's just that niks happens to end in an s.