Japanese leaves out anything the listener can reconstruct, and it leaves out a great deal. The subject goes first and goes most often, the object follows, and what remains in the air can be a verb and a particle. Which means the particles are not small grammatical decoration. They are the only marks left saying who did what, and they deserve more attention than any tense.
The other structural fact is that the verb comes last, so the thing that says what happened arrives after everything that says who, when, where and to whom. A sentence is not resolved until its final syllable, and in a polite sentence the politeness is in that syllable too.
Six patterns that carry the grammar
- 私は本を読みます, I read a book, literally I as for, book object, read. The particles do the work that word order does in English.
- は marks the topic and が the subject, and they are not the same thing. This distinction has no English equivalent, it decides what a sentence is about rather than who did what, and it takes years rather than weeks.
- を marks the object, and it is written with a character used for nothing else in modern Japanese.
- the て form joins clauses, doing the work of and, and also feeding a large family of constructions for permission, prohibition and ongoing action. It is the highest value single form in the language.
- counters: 一本, 一枚, 一人, one long thin thing, one flat thing, one person. Japanese requires a counter with every number and the choice depends on the shape of what is counted.
- たら is the ordinary if, one of four conditionals that differ in ways textbooks explain badly and usage settles quickly.
Two particles, and the argument that never ends
The distinction between wa and ga is the canonical difficulty and it resists the rule everybody is given. Wa is not the subject marker and ga is not simply the subject marker either. Wa marks the topic, what the sentence is about, and it usually carries information already in play. Ga marks the grammatical subject and it usually introduces something new, or picks one thing out of several.
Which is why no rule settles it: the choice depends on what the previous sentences established, so the same clause takes a different particle in two different conversations. A learner who has been taught wa equals subject will produce correct sentences that quietly say the wrong thing, and nobody will correct them, because both versions are grammatical.
What does work is exposure with attention. Take a page of a graded text, mark every wa and every ga, and for each one ask whether that thing had been mentioned before. The pattern is visible after fifty examples and it is not statable in a sentence, which is the honest reason this takes months rather than an afternoon.
The verb waits, and so does the politeness
Because everything hangs on the ending, a Japanese sentence commits late and a listener has to hold it. That is a memory cost on the receiving side and a planning cost on the producing side, and it explains a specific and common failure: a learner who begins a sentence without knowing how it ends has to stop, and stopping mid sentence in Japanese leaves the listener with the parts and no relation between them.
The tense system is small, which offsets some of this. There are two, past and non-past, and there is no future tense at all; whether something is present or future is decided by context or by a time word. That is genuinely less to learn than in most languages, and the space it saves is where the particles and the politeness go.
Two particles, one question
What the choice between wa and ga is actually tracking
Not subject against object. The axes are what the sentence is about and whether the thing is new, which is why no rule about grammar settles it.
The sentence is about it
- The default in a continuing conversation
- Often the first mention, then wa afterwards
It is doing something in the sentence
- This one, as opposed to the other
- Answering who, and describing what is there
The grid describes tendencies rather than rules, and the same clause moves between cells depending on what came before it. That dependency on the previous sentences is why this takes fifty examples and not one explanation.
Two references, and one is free
Tae Kim's Guide to Japanese is free, complete, and organised around the plain form first, which is unusual and is the right order for anybody who wants to understand what they hear rather than only what a textbook says. It replaced the course that teaches the polite form for a year and leaves the plain form for later, which produces a learner who cannot follow a conversation between friends.
A Dictionary of Basic Japanese Grammar is the reference to have beside it. It is paid, it is arranged by pattern rather than by chapter, and every entry contrasts the pattern with the ones it is confusable with, which is exactly what a wa and ga question needs. It replaced the grammar appendix at the back of a textbook, which states each rule once, correctly, with nothing to compare it against.
The mistake: translating the particle
Particles do not correspond to English prepositions and treating them as though they do produces a learner who is looking for the Japanese for at. The particle marks a role in the clause, and the same role is expressed in English by word order as often as by a preposition, so the mapping is not one to one and the search fails.
Learn each particle as a job rather than as a word. This one marks where an action happens, that one marks where something is, another marks the destination and another the direction, and two of those are frequently interchangeable while two are not. A card with a particle and an English preposition on it is a card that will produce wrong sentences with confidence, which is the general problem with storing a translation instead of a use, discussed in making cards that teach rather than cards that pile up.
What the grammar leans on
The particles are written in hiragana and the words between them are usually in kanji, so the script change is showing you where every clause boundary falls, which is ninety two symbols, and the fortnight it takes. The verb ending that closes the sentence is also where the politeness is decided, and there is no neutral setting, in plain, polite and humble, and choosing between them. The words being marked belong to three different vocabularies with three registers, in native words, Chinese readings, and English borrowings. And the characters carrying them are learned inside words rather than as shapes, in readings, radicals, and an order that makes them stick.