What if someone wants something else?

If they demand dixyzx?

What if they demand custom declensions on verbs that involve them?

It's really not that hard to keep a mental lookup table for each person and their custom pronouns and declensions.

Another pretty elegant solution I've found if there's too much confusion amongst our team is to suggest people switch to learning Hungarian which doesn't have gendered pronouns. A few years of intense study is a small price to pay so that we can avoid the catastrophic mistakes of accidentally calling someone who's not in the room the wrong gender

Unfortunately I tried that. After 3 years of Hungarian classes, I had a peer that demanded I speak to them in Klingon because they identified as hypermasculine. Now I have to start over again.

I took Japanese :S

ドイツ語はぜんぜんわからない

"The German language doesn't understand?" :)

(wa should be ga. wa means German is the subject that is doing the not-understanding.)

No, it's fine as is. I think you have は and が backwards but neither of them imply ドイツ語 is "doing something" even though it's the subject of the sentence. It's a pro-drop language so meanings that don't make sense are just excluded.

>I think you have は and が backwards

I do not.

は is not the "subject", it's the "topic", which is different.

I was split between で or は, forgot all about が. Funnily enough I think omitting the particle altogether would have made more sense.

Edit: After further reading は seems to work fine. In this case I think both work but が places greater emphasis on the german language being the thing not understood. で however was totally incorrect :P. But due to the tacit nature of informal Japanese I think the context already informed the reader who doesn't understand what.

Yes, people will understand what you meant if you used wa.

I don't think it's a matter of people simply understanding what I meant to say, it's grammatically correct from what I have gathered.

が marks the subject, and the subject of わかる is the thing that's being understood, not the thing that's doing the understanding. (Maybe you meant subject in the non-grammatical way? It's confusing.)

Either way, は is fine in this sentence to the best of my understanding. It marks ドイツ語 as the subject, and thus the thing being understood.