Yup, this is just a variant of ‘ti’ - ‘chdi’ - I think we mention it the first time it crops up, but I wouldn’t want to bet the house on it either…
The key thing is - say what comes naturally to you, which is fine, and through exposure you will become gradually more used to other ways of saying the same thing… 
More than OK, it would in fact be perfect…
Although as you say, with many learners you’ll want to temper the wind to the shorn lamb by using ‘dwi ddim’…
Diolch yn fawr
That is a Northernism I haven’t met until now. It would really have thrown me!
“Sa i…”. You know it! Negative, used generally, but by no means universally by a lot of people in the South.
Oh dear, mixed up life strikes again! The one I know, but am not sure where it is from:-
“Fe wn i.” - I know; “Wn i ddim.” - I don’t know.
I did learn mostly in the south, but have not met ‘hwntw’ is that what gogs call us? And is ‘sai’ localised at all?
( Sorry’ I thought you were doing the Southern lessons!)
It’s a common form of the negative in the South. By no means universal. The “ddim” form is fine. You’ll also hear “smo, so” or various other forms.
[The rest of this isn’t important! - It comes from “does dim ohonaf i”! There is, apparently, a natural progression in languages for the negative to change over time in this way. The “simple” negative becomes replaced by a more complex, emphatically negative form. Thus simply putting “nid” in font of the word became “not negative enough”, and the more intense negative also using “dim”, originally meaning “any” became used as the normal negative itself. Then “dim” started to replace “nid” as a negative completely, taking on its negative meaning. Apparently the same thing happened/is happening in French with “ne” taking on “pas” as an intensifier, and now beginning to be replaced by it (apparently!) It’s called a Jespersen Cycle.
So this seems (simply a theory of mine!) again, a complicated, more emphatic form of saying “no” replacing a simpler one, then simplifying itself. Not quite a Jespersen Cycle, but very similar!]
Mind you, saying that, the commonest negative around my home village is simply sticking “nag” in front of the sentence, which seems to me a very neat and tidy way of doing it! 
I am doing Southern, mostly. (Well, Challenges now, since they came out I switched from the Lessons.) But if I find something I think I know, but not as Iestyn says it, I try Northern and often, yes, that’s what I knew! Comes of having a mixed up life and an ‘Auntie’ who moved from south to north! Also, the only ‘Conversational’ class I ever did was in the south but taught by a lovely lass from the north who married a southerner! She tried to teach ‘south’ but sometimes, I find, we ended up learning Cymraeg gogledd!
Nothing wrong with that! You were, and are, learning Welsh
Different forms aren’t shibboleths, and like I say, whenever there is a local alternative form, the generally commoner forms will normally be used and certainly understood as well
I’ve been off-line for a bit and picked up on this one this morning. There are lots of interesting things published by David Willis in Cambridge - I have a hunch his work is not universally popular for some reason, but not sure if I’ve made that up. Anyway there is an interesting book - The History of Negation in the Languages of Europe and the Mediterranean. I haven’t got it, but it goes into a lot of detail of all of these things in Welsh, Breton, Cornish and Irish. You can read parts of it from Google books, but some of the interesting pages are not available. Page 290, breiefly mentions sa an so forms, but gives examples of the other variant down South - the Smo forms.
Wahey! Thanks for that. He backs up what I thought and said above about the similarity to but not quite sameness of the Jesperson cycle to the various forms of “sa”, albeit when mentioning “nag” so even if “his work is not universally popular”, I like him on this point!
Diddorol iawn … ond dwi ddim yn gweld o ble mae´r ffurfiau fel ´sa´ wedi dod. Oes na rywun sy´n gwybod?
Very interesting … but I don´t see anything about where the ´sa´ forms come from. Does anyone know?
Said in my post a bit further up.
A shortening of does dim ohonaf i
(Or does dim o).
(Does dim o, smo, so, sa, sana).
Dim o often goes to “mo” in such a situation anyway.
Sorry, but I’m off on another trail at the moment - reliving a phantom conversation that I never started with someone the other day, because I just couldn’t think of expresssing what I was thinking in English into Welsh. My mind immediately in English wanted to say to someone - “I wish I could speak better Welsh” or “I really wish I could speak better Welsh”.
I’ve been surfing this morning and it seems that there are a hundred ways in Welsh of saying what I wanted to say, but I can’t find the way that I actually wanted to say it. I think a common way in Welsh is to say it directly using like etc - hoffwn i etc (not what I want really) or by saying almost the opposite and by implication mean what you intend, by starting with Drueni or O na. It was a topic on the old forum Wales and I’m trying to assimilate ideas and versions now that I might be able to fall back on in the future, but I haven’t found that magic one yet - I think I’m missing something and will know it when I hear it hopefully. Ideas?
Edit: Been getting into a minefield of a grammatical area with this one - I know nothing at all of the imperfect subjunctive forms (or conjunctive) which are meant to convey “mood” apparently in many languages. I found some tables for the irregular verbs and I suspect that some of these are used in normal speaking - I just don’t know which ones.
Shwmae pawb
A question question regarding literary forms of the verb bod. I am reading the book ‘Y Storiwr’ and the form Byddai is used a lot, which I had always thought of as ‘would’, i.e conditional, but many past continuous forms use the same form, e.g. teimlai - he was feeling or he would he feel. Many sentences have made sense translating to both he would and he was, especially like in the English where would refers to the past in some contexts, e.g. ‘He would play in the park every day when he was young’.
So my question is in literary welsh can ‘bod’ conjugated to Byddai mean he was, or is it always the conditional? And if it is the conditional can it be used in the past in the same sense as in the direct English translation ‘He would play in the park every day when he was young’.
Diolch yn fawr am ddarllen
As far as I know, byddai is always conditional, the habitual meaning in your example I think is better conveyed with ®oedd, so roedd o’n chwarae…
@owainlurch is a font of fascinating info! Diolch i ti am yr un 'ma!
I wonder if it would be idiomatic to say:
‘Byddwn i’n reli hoffi siarad Cymraeg yn well’
? Hm, not sure if that sounds right or not now, sorry!
I’m not really qualified to comment, as I only consult grammar books in rare moments of extreme interest. But having read quite a lot of (non-grammar) books, this was in fact the impression that I have got. So I was slightly surprised at @louis’ comment. I wonder if anyone else could confirm either way?
Think I’ll retreat back into my corner now. 
Just to clarify, I don’t think Flynn’s example of “he would play” is a conditional, that’s why I think roedd is better. I think is an example of the habitual past: Http://grammar.about.com/od/fh/g/Habitual-Past.htm Happy to be corrected, though.
Aha, seems I was wrong, byddai can bbe used as well: http://privatewww.essex.ac.uk/~rborsley/wss/habituality.doc
I just found an example from Manon Steffan Ros (about squabbling children)
Byddai ei phresenoldeb yn ddigon i’w gythruddo, hyd yn oed.
Which I had understood to mean:
Her presence would be enough to provoke him even.
My impression from ‘learning by doing’ was that the ‘would’ forms of English and Welsh equate in this kind of sentence, in a way that German, for instance, most definitely doesn’t.
However I just had a ‘reach for grammar book moment’ and frustratingly failed to identify whether this is correct. (I don’t think it’s covered in @garethrking’s first workbook.) Please someone put me out of my misery!
Aha, thank you! I will look at that properly in the morning as it’s not opening nicely on my phone and I am starting to fall asleep in the wrong place…
