Is it me or is the pronunciation of chwys slightly off. She seems to miss out the letter y.
Does chwys mean anything on its own?
Yes, sweat. The verb is chwysu, the adjective is chwyslyd.
This can't just translate to "sweat shirt"? It has to be "a sweat shirt"?
Both are fine. Report it if it doesn't accept the version without the article.
Sweater is not allowed. What's the difference between that and a sweatshirt?
A sweater is usually knitted - - a jumper