Sorry if this is a stupid question and any spelling mistakes but…
I think I’d better go now = Dw’in meddwl bod well I mi mynd rwan.
Dw’in meddwl = I think
Well I mi = i’d better
Mynd = go
Rwan = now
Where does the bod come from? Is it just the English that is incorrect and should really be ‘I think that i’d better go now’?