Long post is looooong. And tautology cat is tautological.If I could go back to the beginning and learn Japanese again... well, a number of things could have been better. No class I have ever heard of really teaches things in the right order. I'm not even sure what the right order is, but I think it might be something like this:
Though I know it would make Tae Kim bristle, I think learning the kanji by the Heisig method (assigning English readings to, and memorizing out of context (at first) all the kanji, plus learning to write them via mnemonic stories) would be best for a beginner of Japanese. It would probably take up a whole semester; a really intense one. However, I wouldn't adhere strictly to the "daily use" kanji, since we all know that list is a bit off; on that point I break a bit with Heisig, but as per Heisig, delaying the Asian readings a bit bring us to the next phase/semester:
Then the kana comes. After that, the onyomi and katakana words. Then lots of 2-character words (finally, context of how kanji work together!), maybe as many as 500 (I would write their readings, at this point in the game, in katakana to subconsciously emphasize the difference from what is to come later). But not one-kanji words, because most don't use a Chinese reading and we don't want to worry about that and conjugation yet, so only onyomi readings, no tricky words with kunyomi reading at this point (no okurigana!), to be followed by longer, multiple-kanji words and 4-character words/idioms (gotta have idioms for fun and a little history helps make things interesting). At this time, だ can be taught to let the students finally be able to make a sentence.*
Following all these onyomi (kango) words would be the one-kanji kunyomi words complete with okurigana and conjugation(also *--you'll see why when you get to the footnotes). Towards the end of all this (at the same time): the beginnings of grammar instruction.
And when I talk grammar, I think the order should be important too. First, the concept that a verb is a complete sentence (and that a copula is a very special verb with limited conjugations!); I wouldn't emphasize the pronouns for a long time (though they may know the kanji and readings for them, students wouldn't get the grammar to use them for a while). I want to make subject-less language seem natural to them. I would cover almost all the verb conjugations (this is during the kunyomi stage of instruction); really show how agglutinative this language is. At the same time, the suru verb concept gets good play.
Following right along should be na-adjectives, because of the special role that copulas play with them, letting you make adjectives (na is da). Then no-adjectives, which should be a short section. After that, i-adjectives, because if we learn them after other adjectives, we are less likely to get na-adjectives that sound like i-adjectives mixed up in our heads when we conjugate (so master those na-adjective+copula conjugations first! Not 綺麗くない！綺麗じゃない).
At each step, I would make efforts to master all conjugation forms (て comes latter though). Anyways, most of the other grammar would come after the base-work had been established. Things like te-form would probably come later in the game; I would incorporate it into keigo instruction because of how often it comes up there (ex: ～てください or ～てあげる etc.), but I would probably introduce the so-called masu-stem shortly after furigana comes around (since it is used for a lot more than just masu). Yes, that sounds good; pretend I wrote that in the appropriate place above. After furigana comes verb stems and kunyomi combo-words.
*: I might let the copula だ loose here, just so they can make a simple sentence, but desu comes much later (note that I don't believe だ is merely a plain です; Tae Kim wouldn't bristle at that). In fact, I would always teach the plain and/or dictionary form of everything first, and maybe even delay masu's introduction (it's a special verb IMHO) . Polite language may be, well, polite, but it's instruction too early is a major problem that 99% of teachers make. Most people learn masu form before anything else; it's a little silly.
The main problem with my curriculum is that it would be long before people had the tools to converse, and the majority of people that take it in college (anime nerds) would probably not be patient enough for it. However, part of the reason why Japanese is hard to learn despite being so simple is because we learn it in a pretty mixed up manner. With the kanji and kana, it can feel like learning 4 languages at once; and they all get crammed in your head, delaying those important realizations that help you through a language. If you master being able to read, however, then encounter how to conjugate and link words in an orderly manner, I think it will be a series of simple concepts building upon each other. Another problem with my system in this post is memorizing words without context could be a bit hard to do, so an earlier introduction of some grammar elements may be necessary to make sentences. But really, no sentences until after the kanji are mastered on the singular level.
A lot of people learn phrasal Japanese ("my name is x, it is nice to meet you"), and while that may get you through a brief business meeting where you have a translator at your side, it will never teach you Japanese. Avoid phrases until you have mastered everything I say. Phrases are the icing that make you sound good and teach you about culture, but you can't adapt them unless you understand them.
So, anybody interested in learning this way? I would like to know how it works. I can't go back and relearn (well, in a way, that's what I often have to do, come to think of it) in real life; I can only speculate from my proverbial armchair. Sometimes I get the crazy idea to write a series of textbooks, but I am far from that stage... The more I look at this post, the more doubts I get about it, but...