There are a lot of resources there categorised and a lot of comments from people discussing them. It ultimately depends what kind of resource you want. There are basically three categories; apps, videos, and textbooks.
Bunpro.jp is probably the most popular website/app as it lets you learn grammar in an SRS system in much the same way WaniKani does. There’s also TaeKim’s Guide, which is a static web based textbook.
In terms of videos, the most popular series are probably Japanese Ammo and Cure Dolly. Really depends on how you get along with the person making the videos and the presentation style.
When it comes to textbooks, Genki is the most well recommended and widely used.
I’m not irritated by this or anything – don’t get me wrong – but there’ve been a ton of threads on the topic of ‘starting to study grammar’ lately, at least one a week for the past month. (I log on almost every day, so I have a rough idea.) Granted, a lot of them were asking about ‘when’ people should start studying grammar, and not so much how, but you might want to try searching the forums with keywords like ‘start study grammar when’ and seeing what comes up. Perhaps some of the advice there will be helpful for you as well.
@Joeni recommended that list of resources, which is pretty great. If you asked me to cherry-pick the most popular grammar resources on that list for beginners, they would probably be:
Grammar sites: Tae Kim’s Guide to Japanese, WasabiJPN, Maggie Sensei (Imabi is also an option, but I feel the writing style and approach is not suitable for beginners)
YouTube channels: Japanese Ammo with Misa, Cure Dolly (Nihongo no Mori also seems excellent, but videos are mostly in Japanese and probably better for advanced students)
Textbooks: Genki, Minna no Nihonngo
If you asked me to pick one per category, I would recommend Maggie Sensei, Japanese Ammo and Genki. Here’s a breakdown of why:
Tae Kim’s Guide contains a few errors and some controversial explanations that only he uses. That doesn’t mean they’re all bad, and I think his guide is probably the one that’s the easiest to follow because it’s structured sequentially like a textbook, but I’d rather learn things that allow me to move on to other resources if I need to. WasabiJPN offers very good explanations and has a very readable format, but I don’t think they’re as nuanced as Maggie Sensei’s. Maggie Sensei’s are the most detailed with the most examples, all written in simple (if sometimes slightly unnatural) English. However, I’ve heard complaints about her colour scheme and the structure of her articles being hard to follow. I’ll grant that there’s sometimes a lot of clear organisation, but you need to bear in mind that she usually covers much more than other sites out there per structure, and that it can be hard to categorise all the different usages neatly.
Cure Dolly’s persona is an android who speaks rather slowly – too slowly for me – and some people find her voice grating. All aesthetic matters aside though, while some of her explanations are very intuitive and helpful, she also pushes a lot of controversial ideas, and likes to present herself as the authority on how Japanese should be taught while sensationalising her ideas as ‘never before seen/taught’. The end result is that a lot of her hardcore fans, who often end up close-minded, attempt to discuss Japanese grammar using terms no one else uses, making them completely incapable of understanding other higher-level grammar resources that use standard explanations. This is not a necessary consequence of watching her videos – her explanation of かける, for instance, is much easier to understand than what most dictionaries present – but using nothing but Cure Dolly’s explanations without trying to see how they translate to other explanations is going to leave you trapped, in my opinion. Japanese Ammo with Misa generally has a much livelier conversational format, and contains plenty of personal anecdotes. I think the way Japanese is spoken there also sounds much more natural. Feel free to try them both – no need to throw the baby out with the bathwater – but I’d recommend Misa over Cure Dolly any day.
Some examples of what hardcore fans of Cure Dolly say and how her controversial ideas clash with mainstream grammar
Fans often say that she shares many of the ideas of Dr Jay Rubin, who translates Murakami’s works, concluding that since they are supported by an eminent translator, they are credible. All I can say is that I strongly doubt that his ideas are widely accepted among the Japanese linguistics academic community, or they would probably turn up a lot more in textbooks, be they for natives or for foreign students. For example, I don’t care if the ‘null subject’ idea – that one should add a が-marked word to sentences like this: わたしは（わたしが）みずをのみます – works as an explanation for what happens when は is used alone with a person and a verb: if Japanese people don’t understand their language that way, then we’re introducing pointless nonsense that can’t even translate into sentences that will be accepted by natives. Also, as another example, blaming Japanese teaching methods for creating confusion between は and が just completely disregards the fact that it is a complex subject, and that Japanese people only use them with such ease because they use them all the time and can simply develop an intuitive feel. If it were that easy to explain, Noda Hisashi wouldn’t have written an entire freaking 331-page book in 1996 entitled ‘Wa and Ga’ in Japanese!!!
Minna no Nihongo is very academic, and requires you to work through pure Japanese text with the help of a second volume containing translations and grammar. It’s of high quality, but will probably be pretty boring to work through on your own. Genki includes a lot more English and is easier to understand. That aside, it probably contains pitch accent guides or allows you to download them from its website, so Genki is much better for developing good pronunciation and natural tone. I also think that the dialogues/texts in Genki are slightly more natural. Minna no Nihongo actually covers more grammar and vocabulary than Genki, but given that Genki is easier to follow and more motivating for self-study, it might be worth the trade-off. Minna no Nihongo is also more expensive, if I’m not wrong.
At the end of the day, these are just my preferences, so you should look for samples and choose based on what helps you most. I will not look down on you if, for example, you decide you love Cure Dolly or Tae Kim’s Guide. Just please don’t become a close-minded person who’s unable to handle any other explanations if you choose those routes. Some people on the forums have used them for study and are doing just fine, so again, what matters most is what helps you learn best.
I actually started with Tae Kim’s guide and did most of it, and in terms of pure grammar points, it’s a good resource, but he (Tae Kim) often misses a ton of nuances which for instance Genki covers, like the various uses of 方 in comparisons and giving suggestions. I’m not sure which of his explanations are controversial specifically, but some were incorrect either through omission or just wrong. Thankfully, Genki managed to straighten those up already .
I haven’t seen any pitch accent guides in Genki so far (at chapter 15/23, currently), but either the books come with CDs with dialogues or the tracks can be downloaded from Genki’s website. My copies didn’t have CDs with them, but links were mentioned in the initial sections of book 1. Other than that, I think Genki is a great resource, because apart from grammar it covers useful day-to-day topics, cultural elements, etc.
@Alexander_Staus I think as a general rule it’s good to rely on resources made/written by Japanese people. They aren’t always perfect, but at least you get a grasp of how they use their language. And the more different ones, the better so you get a broader perspective.
Finally, it’s never too early to start with grammar. If you have the time, it’s good to do it already .
Oh yeah, Miku’s channel is good too! I forgot to mention it. I believe she’s from Osaka, but what she teaches and speaks on her channel is standard Japanese. She also did a little episode comparing Kansai-ben and Tokyo Japanese, which was pretty interesting.
@AndyMender Here you go. I don’t know if they’re still relevant to the current editions though, and I don’t know if they’ve been updated since they were uploaded.
There are playlists in her channel and each video covers a different grammar point. Like there is #1 for people who are absolute beginners and have no knowledge of grammar then at around #20 the playlist changes to Upper Beginner and so on. There are also playlists for people preparing for JLPT though they are not that detailed. She only does till N3 which is understandable.
Well, it’s good to hear that she organises things in a way that’s easy to follow. One of my favourite resources, Maggie Sensei’s site, probably doesn’t have a recommended order for lessons, even if lessons are organised by JLPT level. That might be a bit disorienting for beginners. I only use it for looking up grammar points though, so that doesn’t affect me.