Yeah I guess I just found that comparing my grammar practice to stuff like your project (which was very helpful, so thanks for that! 
) and also using ET’s grammar tree prompt (which sometimes makes errors, but I still found it to be helpful) was enough.
But now you mention it, and since I’m moving on to stuff that’s more complex than “John threw the red ball”, I might start a grammar thread at some point. So thanks for the suggestion.
That’s a very generous offer. I don’t want you to feel obligated to check my stuff though, so it’s fine if you don’t.