The phrasing of this section is (ironically) kind of awkward, but I can see the idea. Again, substituting parts of the sentence with phrases of similar meaning like “to be” is helping to put everything together. However, “as” it piling up complications around it, and it’s starting to feel like “as” is going to cause a lot of problems later on, considering I don’t think I’ve seen it used it any of the book’s exercises, at least not recently. The fact that it can’t fit into sentence 10 patterns, but only usually, is already making me dizzy.
I completely agree. The tests we were given, such as the “to be” test are very clear and helpful. However, Even just reading about how expletives works got a little confusing, with or without tests. I think practice will help with this overall, so repetition with this pattern diagram will be the best thing for me to better understand the concept.