I would not call this gatekeeping, I would call this a simple (albeit loud) critique, and maybe a reality check. Gatekeeping is when someone new is not allowed to enter a certain space, but people here are simply pointing out that this article is not the expert opinion of somebody that know how to teach Japanese verb conjugation, and that tutorials like these, while not harmful, are not super useful either.

Learning Japanese is fun, and I encourage the author, and the readers of this post to continue learning. But my advice to new learners is to just get a textbook (or some structured material; but please, just get a textbook unless you are one of the minority cases where you can’t for the life of you follow a textbook) and learn the conjugations little by little as they advance through their textbook (or their alternative structured material) one chapter at a time and consume more and more advanced Japanese language material over the course of dozens of months.

For the people who do that, I promise you, if you study for an hour or two a day, just following some structured material aimed towards beginners (preferably a textbook) and engage with the language as frequently, you will intuitively understand and be able to produce the mostly correct (i.e. with diminishing errors) by 3-6 months.

> Wow, there is a lot of negative gatekeeping on learning Japanese in this thread. I recommend people chill out.

Any discussion of Japanese here brings out a lot of extremely defensive nerds. I don't know why this happens more with Japanese, but it sure seems to. I don't have a strong opinion on the post, and I tend to think that if you find something that works for you, when it comes to languages, you should go with it. Far be it from me to tell you that you're wrong for learning how you learn. But that said -- and as others have noted -- the explanation here is misleading, and that's because of the dependence on romaji / transliteration. Japanese conjugation is extremely simple, and the author is missing some essential context that would make it all much clearer. For example:

> it's not entirely clear what nomu's stem is. is it nomu? but then, we define stem as the unchanging part — whereas the last vowel seems to alternate, like nomi or noma in some cases.

First, there is a clear stem (飲＊), but you just don't know that yet, because you haven't learned kanji [1]. The conjugation is extremely regular, and there's no reason to memorize a bunch of granular rules like this:

> む (mu) changes to み (mi) when adding ます（masu)

To wit: a godan verb [2] shifts from the "u" sound（う・く・す・つ・ぬ・む・る・ぶ・ぐ / u, ku, su, tsu, nu, mu, ru, bu, gu）to the "i" sound in the same column of the kana table（い・き・し・ち・に・み・り・び・ぎ） when conjugating to the formal (aka "teineigo" / aka "masu"）conjugation.

It's one rule. Then, for casual negative conjugations, you shift to the "a" sound in the same column (わ・か・さ・た・な・ま・ら・ば・が). Two rules. Formal past tense, and a bunch of other tenses derive trivially from these (e.g. わかるー＞わからないー＞わからなかった / "I understand", "I don't understand", "I didn't understand"）

That covers the conjugations the author cites in the piece, and a few others that he hasn't. However, for past tense or て form, the author's system will actually confuse you (IMO), because the you really do need to have an intuition for kana to know how the conjugations are going to play out. Namely the following rules:

る・う・つ becomes って or った (continual or past tense, respectively)

く becomes いて or いた

す becomes して or した

ぐ becomes いで or いだ

ぬ・む・ぶ becomes んで or んだ

For these, it's really, really, really helpful to just know kana, and how the sounds roll off the tongue. Because if you do, you quickly see that there's really no other way for the first three endings to work out, and require little/no memorization at all. The last rows are the exceptions that you have to learn. But again, it's what...7 rules in total? In the grand scheme of language learning, this is nothing -- and boy, let me tell you, if memorizing seven semi-arbitrary things is a burden for you, Japanese is not your language.

Anyway, the point is, I strongly encourage you to learn kana as quickly as possible, and then onto kanji forthwith. The sooner you do this, the sooner all will be made clear!

[1] I am using the royal "you" here. I don't know if the author knows kanji and don't care; I'm saying that if a regular person is at this stage of learning Japanese, they will not know many, if any, kanji.

[2] Just doing godan verbs here, because ichidan verbs are much simpler. The tricky part of ichidan verbs is knowing which ones they are, which, alas, you mainly just have to memorize. You can sorta-kinda infer that a verb with an "iru" or "eru" ending is ichidan -- it's always true that ichidan verbs end like that! -- but it's a necessary-not-sufficient condition, which, again, requires that you know the kanji to distinguish "without memorization."

Look at all the text that has been spilled for just a simple thing that could be explained adequately by "col(す)+row(い)=し". There is really not much point studying grammar if you don't know grammar first, much like studying bigfoot. People have strange hobbies, but we also have a ethical obligation to prevent young people from deluding themselves (and not sell them bigfoot nets) when it comes to topics that require a lot of time and energy.

In language learning you can run into a whole host of category errors and waste your time, learning words, grammar, culture, JLPT, hepburn, lingusistics, prosodic theory, an app, kanji instead of the language. It's a trap that obsessive people often fall into when they should have been listening to tapes until they can differentiate the sounds, match them to words and chatting with locals. Which is unfortunate since after learning the language these obsessive types could ace the JLPT no problem.