"Usually I am not sad."
Translation:Zazwyczaj nie jestem smutna.
Then if this is the case, why aren't both marked as correct? How is one to know whether to use the formal version or not?
Both are accepted. Is "zazwyczaj" more formal? I don't know if that's a good word, but okay, let's say it's a bit more formal. Or more bookish. But just a bit.
I didn't think Polish had a word order. Is there a reason why 'zazwyczaj jestem nie smutna' is incorrect?
It's hard for any language to have 'no word order', even if it's relatively free. Your sentence means something like "Usually I am not-sad" with 'not' negating 'sad', and not negating 'being', as it should. Keep 'nie' before the word it negates.
Also in most contexts, 'nie' with an adjective in its basic form is written together: bezpieczny/niebezpieczny, duży/nieduży, etc.
You are everywhere on here! Your comments are always useful, so thank you for all the help.
yes, it is not correct. this word order can be used in case: "Zazwyczaj jestem nie smutna, lecz wesoła"
The example given by herylia is good as it is. No need to change word order.
Adjectives are gendered. "smutna" is what a woman will say. "smutny" is what a man will say.