In this section on dialects the contributors have added phrases important to their part of Wales. 'Chdi' is used instead of 'ti' for the informal 'you' in the part of Wales, the North-West, where Welsh is most widely spoken as a community language. 'Rŵan is used in the whole of North Wales as 'now', while 'Nawr' is used as 'now' in South Wales.
I imagine the reason for including this phrase, since I didn't add it, is its use in family situations with children, for example preparing children for a bath you would need to tell a child 'chdi rŵan' when it was their turn, or maybe taking turns on a swing.
This unit on dialects was very much a trial and error exercise as we attempted to put the quart into a pint pot, ie integrate two courses into one. We will definitely expand on this when we get a chance to revise the course.
The formal registers of Welsh are pretty much standardised, being derived from the very formal Welsh used in the Bible of 1588 and modernised in subsequent editions such as the most recent update of 2004. Modern formal written Welsh will use very similar grammatical patterns to the 2004 Bible but obviously with a vocabulary and style suited to the subject.
The Welsh used in the publications and web-site of the Welsh Assembly represents a normal formal register of Welsh used in official publications, formal speaking and so on.
The patterns used in formal registers are well set out in grammar books by established authors such as David Thorne, Peter Wynn Thomas and Stephen Williams.
Journalistic web-sites such as BBC Cymru Fyw and Golwg360 also use fairly formal Welsh, similar to the same sort of English the BBC and broadsheet newspapers use.