In Lesson 14 (new Level 1) I’m sure I heard “…who knows your sister” translated as “…sy’n nabod dy chwaer di”. What does “di” mean? Gary
Hi, Gary – You’re encountering one of Welsh’s charming habits, there: pronouns are ‘echoed’ before and after the noun, in spoken Welsh.
So what you’re saying is "…who knows \<1st part of your\> sister \<2nd part of your\>. In written Welsh, the second bit is often omitted, but it’s normally included in spoken Welsh. You’ll get the hang of it!
[Edited by Kinetic to fix escaping of angle brackets :)]
It’s kind of like saying “your sister of you”, which sounds weirdly redundant in English, but actually sounds totally normal in Welsh 
Yeah; possessives in Welsh are a little odd. Di is a softened form of ti; which you’re familiar with as you. As far as I can tell, the dy, or fy, ei, eu, eich, or ein, aren’t really words per se; they’re more markers to tell the listener that the word that follows is to do with the related pronoun which comes after (if that makes sense). The same marker isn’t introduced this way in the new course, but was in the old Southern course at least, in that a lot of people would say “to do it” as “ei wneud e”; using the same pattern as for possessives.
It’s kind of like how in French ne isn’t a word; it just lets the listener know that you’re planning to use a negative later on. Quite commonly, the pronoun is dropped from the end in possessives, while the marker is quite commonly dropped from the beginning for verbs, but a lot of people do use both marker and pronoun for both.
Technically speaking, the “markers” are indeed words, just as much as the pronouns at the end are - in fact they’re possessive pronouns, and are equivalent to English “my”, "your’ and so on.
Thanks to Stu Bonham’s sterling work, I was just listening to one of the Catchphrase hospital soap episodes where they were saying that in the spoken language, the “fy” possessve for “my” is almost always dropped. I’ll have to check again, but it’s either dropped entirely, and the noun is followed by “i”,
Or it changes to sound like “yn” (I think). I seem to remember Gareth King writing something similar in his Comprehensive Grammar.
Now it’s been a while since I did the relevant lessons in SSiW, and I don’t remember it being said that the “fy” was dropped. Presumably it will never be actually incorrect to always include it, but will it sound over-formal or over-fussy?
In Southern Welsh, fy is typically pronounced yn (or ym if before an m).