Regardless of what people think, the grammar vernacular needs to be taught and practiced. I wish, instead of using the phrase "joining words" it said "conjunctions" [or you could use both together to reiterate the function of conjunctions]. Additionally, I think specific reference should be made to whether the conjunction is "coordinating" or "subordinating" to explain why conjunctions appear or "go" in certain places in a sentence. Just my two cents. I actually REALLY LOVE Quill. I am so glad I discovered it five years ago. Thank you so much!!