We are not using ja. We would say just piszę. Ja piszę is unnatural
It depends on situation. There are situations when "Ja piszę" sounds natural.
My answer was "I drink". I think I need a break!
Why not "I write"?
It's also an accepted answer.
No, it's not, it was marked as wrong
I have a report "it write" from yesterday, so it seems that it's probably yours, it's hard for it to be a coincidence. So that was a typo, then.
Why is it not something like Ja piszam? I am royally confused
There are different types of conjugation and the ending -ę is popular for many first person verb forms.
Are there different endings due to different verb types?
I think it's only -ę/-ię and -em/-am.
How can I recognize, which ending I should use? Or, I have to just remember ?
See here: http://grzegorj.cba.pl/gram/pl/odmiana2.html
It's in Polish, but after translating a few words it should be useful.
Is there any rhyme or reason to -am endings and -e endings? Is it all memorization?
No well pronounced. We hear pisze! and not piszę.
It's pronounced correctly.