In Danish, it's risen though. Wonder why it's riset in swedish
It could be that Danish uses common gender for the rice sense and neuter for the brushwood sense, while Swedish merged the two some time ago. This is just a guess, though.
I noticed the AI voice accented the "i." Is this correct, or should it just be pronounced "Ree-set?"
why "et and not "en"?
Swedish words have different grammatical genders. Some are en-words, some are ett-words.
How to tell when it's "-et" and when it's "-en" added?
There's no rule
I suggest you learn the word with the en/ett
(Ex. 1: en banan = a banana)
(Ex. 2: ett äpple = an apple)
There are lots of rules - search for Swedish declensions.
Depends on whether it's an en-word or an ett-word.