Sut wyt ti & Sut dych chi
In school I was taught that 'How are you?' is 'Sut wyt ti?' (South Wales). As for Duolingo it is 'Sut dych chi?'
Is there a difference depending on context or location? Or is it just generally just another way of saying it?
I never learned Welsh at school, I come from a time when Welsh in the valleys was frowned on (!) but as an adult learner I found out that there's formal and informal, like "Hello, How are you?" or 'Alright butt?" I think you'll work out which is which. And then there's North Welsh, just to confuse the hell out of you!!!
Sut dych chi (or dach chi in the North) either addresses someone formally, politely (something you would choose to do to someone you hold in high regards, have great respect for or who is older than you). It also addresses a group of people, kind of like the American y'all.
Sut wyt ti can only be used to address one person and is very casual, addressing (close) peers and children.
Context, yes. Sut dych chi is formal, while sut wyt ti is informal. The verb form you use with either the formal chi or the informal ti pronoun is different, so you have to use the correct verb form for each.