DS is what I would call semi verbal. We did a 3 part makaton course but he didn't take to it because the hand movements stressed him out.
He can tell you what he wants/needs but there isn't much back and forth and alot of his speech is scripting and inaudible to most people.
He's definitely making progress and sometimes he'll really surprise me, like this afternoon for example.
After he smashed the tv he went for a nap, when he got up he wanted cbeebies on so I had to explain that it doesn't work anymore. He went to the back room and pointed on top of the cabinet (where I put the last little tv that he broke a fortnight ago) and said as clear as day "we have that one" 
DH has bought yet another cheap one from gumtree and I've ordered a screen protector for it which should come Monday. I just hope it survives that long.
Thats £120 for the tv and £90 for the screen protector so we won't be going for our exceptionally rare Valentine's meal now (you can see how the cracks start to show eh)
I think going on some courses is a good idea if anybody can reccomend any particular ones that I can do in person? I did the Understanding Autism one with the OU online but to be completely honest it didnt tell me anything I don't already know.
Upon reflection I think both me and DH dropped the ball today.
DH gave him and DD smarties as a treat at lunch time. We don't allow sweets often purely because they almost always cause problems so he dropped the ball with that, but I didn't step in and say no.
DD eats them but DS likes to line them up, put them in cups etc. DS wanted DD's aswell as his own and that was causing conflict between them and he was getting frustrated.
Then I didn't give him ample warning before I took him to change his nappy (you raised a very good point Muddling and I should've considered that. We was in a rush)
I can see how the impromptu nappy change when he was already frustrated was the straw that broke the camel's back.
The benefit of hindsight eh. I guess I'm still learning and hopefully in time these things will become a rarity.