I have a 4th grader who has completed the First Language Lessons curriculum. He struggles with writing sentences (often leaves out words, writes run on sentences and misspells), and we're working through that this summer (I haven't done a formal writing curriculum with him and only spot-check narrations.) I also have a 7th grader whose elementary grammar was in a hybrid school using a public school textbook (Sadlier Grammar Connect), and in 6th grade we started with Classical Conversations English Language Lessons, did some lessons from First Language Lessons, and completed a Khan Academy grammar unit. He thinks grammar is pointless because he knows how to write sentences and speak correctly, so why does it matter which part of speech a word is? He's a strong writer. Should I start them both in the purple book or put the 7th grader in a higher level?