One of the things i find difficult in speaking welsh are those little almost throwaway phrases i use all too frequently in english.
Stuff that often fills conversations while you think about what to say next.
You know things like “on the other hand”, “apart from that”, “quite possibly”, “don’t mention it” etc etc.
Hoping level 3 contains stuff like this 
I write down expressions like that when I’m watching S4C or from the dialogues in textbooks and reading books and then try to make small dialogues with them. Or there was a forum (now inactive) for native speakers and advanced learners of Welsh, maes-e, where there were informal discussions about everything from language to sport, and I picked up some expressions there. (Forums are one of my favourite places to pick up new language, since, living in Belarus, I get no exposure to real life French or Welsh, and the language people use on forums usually corresponds to what they would be using in real life).
But a real course with such phrases would be priceless, of course:)
Yes… .i’ve found some stuff on memrise with lots of stuff. But i need some clarity on use.
Eg.
Dwi’n gwybod am hynny trwy brofiad (i know about that through experience).
Wnes i droi tuag ata fo a wedyn o’n i’n synnu i weld fy ffrind (I turned towards him and then i was surprised to see my friend).
Just to add to this i’ve recently come across oddi wrth
Eg (hope this is correct)
Mae gen i lythr oddi wrtha fo, a dwi’n teimlo’n bod ni angen trafod hyn, wyneb yn wyneb.
That one can also be used “as is” in greetings cards, and the like, e.g.
"Penblwydd Hapus Pete!
oddi wrth,
Mike