As a relatively new homeschooler, I am perhaps overly worried that my kids won't learn the right things and will fall terribly behind in the Important Skills of school-land.
Not surprisingly, I bought a grammar book to work through with my second grader right away. I thought Critical Thinking's Editor In Chief looked promising. I guessed it was the right level - the cover said for Grade 3-4, but my special snowflake was reading 4th grade books, so I thought we were all set.
First (and this is on me, not the publisher)-- the book was too hard. My daughter might read at a fourth grade level, but she certainly doesn't understand grammar or spelling at that level. The work was too hard for her to do independently.
A few thoughts about this book:
I love the format. It introduces important rules with clear examples. Then, it proceeds to paragraphs with a number of errors. You are told how many errors and expected to find them.
I love the content. The focus is on common misspellings and tricky situations. THESE are the important skills I want my kids to have - look over text and figure out what is incorrect and fix it.
It's digestible. The pieces come in small bits, so a paragraph or two is great for a short session. The answers are in the back, and are quite clear.
My biggest complaint is that it is sometime pedantic. It teaches rules that I never knew existed....
I have never learned why some words end in -ible and some in -able. However, I was a broad reader as a child and I learned these things intuitively. I don't know that it is important to learn these rules if you can simply become comfortable with a large vocabulary.
Maybe that is the big lesson of this book - early grammar and spelling is taught through broad language experience - hearing, reading, writing and correcting. Perhaps one doesn't need a book to make that work. I strongly support the no-nonsense vibe of the Critical Thinking .com folks (there are no Star Wars themed math books here!), but I wonder if I have over-thought the vocabulary and should just be thrusting that copy of Black Beauty that I found at the thrift store into my daughters' hands.
I agree that grammar and spelling primarily are learned from exposure to the language and will become an intuitive skill. This is definitely true for your native language and to some degree also when learning a new language. Knowing the grammar of your own language will be a great help when learning another new language.
We have not done that much grammar yet with our kids, 7 and 5 years old (and 9 months) we will do more as they get older.
I was and am a prolific reader and writer, and exposure to and production of GOOD, and above all - accurate, language was paramount. In my own homeschooling experience, my parents didn't focus on the mechanics of language until I was 11 or 12. We started out with copying and then dictation so we were able ease into the production of correct language. My father, who was a stickler like no other, would put an "x" (or more than one - depending on the number of mistakes I generated) next to the line with the issue (spelling, etc.) and we had to figure out what the problem was. The writing also was never a decontextualized paragraph out of a workbook, but rather we always drew from topics that interested us. I am now pursuing my Ed.D. in education, and mechanics is typically not an issue that arises. :)