Hello! I have looked on forum and seen there has been some discussion about taswn etc but what I really wanted to find out was where do they come from? I can’t find them in dictionary at all …? Does ‘awn ni’ come from these as well?
Thanks! At Challenge 20 of Level 2 
taswn comes from pe taswn (the pe here = if, and the taswn is a conditional tense of bod)
there are several variations meaning the same thing - pe baswn i. pe byddwn i, pe bawn i, pe tawn i… which you hear will often come down to dialect and the pe is often omitted anyway.
it’s not the same as ‘awn ni’ - that is a different tense of bod and is a ‘we’ construction, not an ‘I’ construction but don’t worry, it’s easy to get confused with bod, as so many endings are similar!
Thank you, as always, for your prompt reply! I feel much clearer now