I’m a native speaker 
what I meant was it’s not completely wrong to say English has three tenses either — there’s past, present and future according to Grammarly (that’s also what natives are taught in school, and therefore what they believe).
But if you look at the website underneath, it says there are twelve basic English tenses. This would most likely refer to adding models or context, like you said.
It just depends on what people mean by ‘tenses,’ I suppose.
In Russia instead of drawing fancy diagrams, we’ve used (at least in 2000s, dunno now)
Makes me wonder how people in other countries mark up their sentences.
Ah, yes, I had the same thing in school in Polish classes
You need only picture the UK.
Sadly, for the majority of us who come up through state schooling, the quality of education can run the gamut from barely adequate, to an absolute failure of the system. Having come from a strictly working class area, attending a school that would have languished in the bottom region of the league tables, I can vouch for the latter. It would be no exaggeration to say some of my peers left school at 16 without an ability to spell correctly, let alone understand grammatical nuances.
To reiterate what OwenDG said, a lot of English native speakers have an intuitive feel for the grammar, but they couldn’t explain why something sounds “wrong”. I would be one of those people. Hell, I would have been in my 20s before I could tell you the difference between a noun, a verb, or an adjective.
It is embarrassing. I feel ashamed of my inadequacies. But, this is the reality for so many children (and adults) across the UK. You’d be forgiven for thinking “they” don’t want us to know any better. 
Same thing for my country. (Moldavia)
We did something similar in spanish classes too, not sure if we used colors or what, but whe underlined and marked each word’s function and/or category.
And to think Mr Gove now has tiny children learning ‘fronted adverbials’ at the cost of their natural enthusiasm to read and write. Grammar is an obsession in English primary schools at the moment (imposed from the ‘them’ you mention, I assure you). Be careful what you wish for.
I’m a native speaker too. Got taught that there’s three tenses in elementary school, more than ten in middle school, and two in a university linguistics class…
I can’t speak a great deal for English primary schools, as I was brought up in Scotland; nor the current curriculum, as it’s been almost 25 years since I was in primary education.
However, I don’t wish that children’s enthusiasm for learning to read and write be bled dry over their grammar textbooks. My reply is more to the poster who couldn’t fathom not knowing English grammar — unless people hadn’t gone to school. Because I went to school, and left without said knowledge. A good balance is key.
I actually think it’s more to do with knowing words like suffix, prefix, transitive and intransitive. Stuff like that. My fiancé is a native English speaker but doesn’t know what a noun, verb, or adjective is. So I think OP is referring to that.
As a professional English teacher who understands the differences between different types of conditional sentences, I can recognize when Japanese does something similar or does it in a different sort of way. I also can recognize certain patterns by noticing which part of the sentence is being modified. So, I’d say that it helps to be able to understand how the languages work and are distinct… the terminology doesn’t matter as much as understanding why and how things change (the terminology simply helps in creating some shared vocabulary for discussing rules).
Yeah, definitely! Just browsing these forums, I’m overwhelmed by all the English terms being used that I don’t know…it’s certainly making learning Japanese grammar that much more intimidating.
You’re right. Come to think of it, there are many terms that I have forgotten because it’s been ages since I’ve learned them. I know the rules but I could not tell you the proper name because some of those have ridiculous names Lol.
You should know basic terms and concepts but the more esoteric stuff that only English teachers study is probably not necessary. If you come across an unfamiliar term just look it up.
Yep. All the terms and rules? I know nothing about those but I still use them without thinking since I’m a native English speaker.
Seems like what you need to do to get good at grammar is read the rules and lots of practice until the breaking of a rule feels off.
Thanks to everyone who’s replied! Asking the forums sure is better than pondering for weeks on end.
Just adding something to the topic of learning grammar in school.
Here in Italy we study Italian grammar for 10 years, from elementary school to the first two years of high school.
In elementary school we learn how to conjugate verbs (there are ~20 tenses, double if you take in the reflexive form, “riflessivo”, and there are three types of verbs and some of the second and third types have exceptions). Here we search for subjects, adjectives, verbs and etc. in phrases and point them out.
E.g.: io mangio una mela (I eat an apple) → io (I) subject; mangio (eat) verb conjugated at present for the first singular person; una (an) article (here we call it “articolo indeterminativo”); mela (apple) direct object (complemento oggetto)
During middle school through high school we study more “advanced” grammar and start studying periods (a group of phrases all connected logically) and entire parts of phrases.
During all those years, we even study English grammar as well as a third language grammar (during middle school, for me it was French)
I have learned three languages (English, French and German) close to fluency without knowing the terminology, so it’s probably not necessary. From top of my head I cannot tell what a “noun”, “adverb” or “conjugation” mean without looking up the meaning from Google. I have probably been taught these when I was 10 years old, but I have forgotten and/or the words for these concepts are completely different in my native language.
I would definitely try to learn whatever grammar you are learning in Japanese in my native language first, just so it is one less dot for me to connect when I am trying to learn the language.
Probably unpopular opinion, but here you go.
you should learn english grammar, not for the sake of learning Japanese grammar unless to comparing from scientific-linguivistic perspective and in hindsight.
From standpoint of learning japanese, You should learn Japanese grammar SEPARATELY and INDEPENDENTLY for its face value. Thats just easier.
A lot of times in textbooks tried to fits English rules and classifications into japanese, while more often than not, you could just simplify japanese and understand better and faster, by just learning it from zero without any attempts to fit in English anywhere in sight.
You could learn more on that from Curedolly organic japanese.
And yes, i am her shill.