I've had two small breakthroughs recently.
The other day, when I came home from work, one of my sons initiated a short conversation in Welsh. He asked me how I was (Sut wyt ti?) and I replied that I was fine (iawn). I then asked the same question to him and he replied that he was happy (Dw i'n hapus). I was very pleased that he had the confidence to initiate a conversation in Welsh (albeit a simple one), and to be ready to answer a question when it was addressed to him. If I'm lucky, before long, I won't have to go outside my front door to find another Welsh speaker
The second was a couple of days ago when I was listening to Radio Cymru. I was able to consciously deconstruct the word 'adeiladol' to work out what it meant. I managed to pick out the word 'adeiladol'. I don't think I had come across it before but I was familiar with 'adeilad' (a building) and was aware that you could add the suffix '-u' to turn it into the verb 'adeiladu' (to build). I had also come across adjectives like 'diddorol' (interesting), and supposed that the '-ol' suffix must make it an adjective. After thinking for a short time about adjectives relating to 'building', I managed to work out that it must mean 'constructive'.
I am sure that as I have been working through the SSiW lessons I have been subsconciously acquiring the ability to construct/deconstruct Welsh words but it's very nice when you suddenly realise that you have that new skill and that you can apply it appropriately.