'moyn' versus 'eisiau'
I'm not yet completely sure whether this is consistent across sentences, but throughout much of the course, 'moyn' and 'eisiau/isio/isie' are treated as lexical variants of each other. Thus, 'Dw i eisiau cysgu' is accepted if and only if 'Dw i moyn cysgu' is. Furthermore, since 'eisiau' does not occur with the particle 'yn' (since 'eisiau' isn't a true verb), 'moyn' is also not accepted with 'yn'. However, I'm pretty sure (and can cite Modern Welsh: A Comprehensive Grammar by Gareth King) that 'moyn' must occur with 'yn' (at least in the environments that other verbs require 'yn' in), so Duolingo is actually teaching ungrammatical sentences like *'Dw i moyn cysgu' instead of 'Dw i'n moyn cysgu'.
Are there plans to change this? I can imagine this being rather difficult to accommodate from the course designers' side, but I would also think that removing 'moyn' altogether would be better than teaching an incorrect use of 'moyn', especially for those who plan on speaking Welsh in the south of Wales!
Or, is the generalization that 'moyn' must occur with 'yn' actually incorrect, at least in some dialects?
Diolch yn fawr!
Perhaps best to just keep marking any dw i moyn... sentences without the required 'n as 'incorrect or unnatural' - Duo will hopefully correct them during this beta period.
I was taught that moyn should always be preceded by "yn", but in practice, talking to first language Welsh speakers in the south, many/most tend to drop "yn". I definitely seemed to hear "dw i moyn" far more than "dw i'n moyn".
Well, I have covered the skills which teach moyn and Duo does require the yn while eisiau does not.