When i studied the videos on here it told me to ask people things differently to how my uni course tells me, and im not sure that it is a matter of dialect.
example in uni it states… “sut dych chi” or “ydych chi’n siarad Saesneg”
but in the videos online, something like ot’n moin mynd?
can you tell me the difference?
This is “how are you” and “do you speak Welsh” using the polite/plural form of ‘you’ (chi).
This is “wyt ti’n moyn mynd” which means “do you want to go” using the informal/singular form of ‘you’ (ti) and the southern word for ‘want’ (moyn)
oo i get it 
Diolch
also, could you spell out “ydych chi’n” how you would say it?
thanks
well it will vary slightly depending on dialect, but:
ud - dach - ch-een
ud as in udder - da as in dad + the ch sound you’d hear in the scottish ‘loch’ - ch as in loch + een as in seen.
or
ud - duch - ch-een
ud as in udder - du as in dud + the ch sound you’d hear in the scottish ‘loch’ - ch as in loch + een as in seen.
Iawn diolch, we were doing the “ud - dach - ch-een” un. It would be nice if everything was the “wyt” un
you’ll find the wyt one is actually far more common in spoken Welsh, but it’s best to know both forms because there are occasions when you need to use chi