McTag, you said in no uncertain terms that 'grammar schmammar. It can ***k with your brain and I think there are more important things to worry about than parsing sentences. '
Ah but if that is so, you would not be coming and nosing round a grammar topic in an English forum... or would you? Personally I think life's too short for macrame, football, and pet cats, but I don't go to the web forums (fora) of their aficionados.
The window was broken by McTag. is passive.
When I was writing the Collins English Dictionary we did make a new category for adjectival use of other things like verb participles. Modifiers, we called them. It hasn't really caught on, but there is a case for them. The def of an adjective may rest on its being modifiable in its turn - a partly closed window, a long-running debate. Or maybe not.
I'm just thinking random thoughts here. Just muddying the waters a bit.