"I am wanting two pounds."
Translation:Tha mi ag iarraidh dà not.
Yes you're right, it is a little more complicated than I put it, I was just giving the basics. "gumpot" is a great way of remembering the sg, sm, sp, st rule - thanks! There are other exceptions too where, say, from the grammar you might expect lenition, it doesn't occur. So it's not as straightforward as it first may seem. All learnable eventually though with enough practise!