I've tried writing in my mother tongue. And it's not working. Something is very very wrong in my world. But then I noted that I kind of have the same problems when writing in English too.
Here's the thing: My dialogue sucks.
Fortunately, this is an issue that can be fixed. I've noted that all I need to do is to read what the heck I've written... and revise it. It's just that I really, really, really need to develop some sort of protection mechanism when I look at the dialogue I wrote: It's not necessarily the most beautiful thing in the world.
I guess there's a good chance I'll eventually be able to write good dialogue all the time, but now it seems that I really need revising and rewriting when I write in Finnish. Rusty skills, very rusty...