“Quick question; what is the difference between は and が?”
It’s a quick question, to be sure, but it doesn’t have a quick answer. Canned lines like “は is the topic particle” or “が is the subject marker” are rarely of any help; the English and Japanese notions of “subject” don’t map 1:1 to each other, and the concept of grammatical topic is unlikely to strike home intuitively for a native English speaker. These one-line explanations are perhaps useful to people who have studied linguistics formally, but as a fan of more naturalistic language learning processes I (personally) never find them to be helpful, and I have no interest in diving into theory in order to make sense of them.
My chosen strategy was to not worry about it and just read until I had had enough exposure to the Japanese language that I was able to form a somewhat intuitive understanding of these two particles (plus one more which I feel is often overlooked despite serving a similar function). You can absolutely do this too, and in fact I would strongly recommend that rather than approaching the problem by trying to learn “when to use は vs が”, you instead pump the brakes on output and focus on getting exposure to a LOT of the language so you too can build up this intuition.
However, since I fully recognize that I’m probably a little weird for being comfortable with this kind of delayed gratification (and since the question above is just so, so common), I thought I’d try to put into words the simple one-line rules that I personally use to conceptualize these two (or three) tricky particles.
The first two particles on this list, は and が, serve similar functions; however, they do it in different ways. To sum up the difference between them in a few words:
は specifies by excluding all but one specific thing が specifies by including only one specific thing
At first glance this may seem redundant. At the end of the day, one “thing” has been specified, and now we’re going to talk about it. What exactly is the difference? All the difference in the world, in fact. Let’s dive in.
When you use が to identify something, you are explicitly only making a statement about that one thing. No implications are being made about anything else at this time.
The reason we typically use が when talking about things we like (e.g. 読むのが好きだ, “I like to read”) is precisely because of this lack of implication. While it’s true that I like reading, I don’t mean to say that it’s the only thing I like, or indeed that I dislike anything else in contrast.
When you use は to identify something, there is a potential implication that the statement you are about to make is only relevant to that thing. This contrast is not always present, but you may be surprised at how often it applies.
The most common use of the は particle is simply to bring into focus the overall topic of our current conversation. In this case, we limit what we are talking about to some small subsection of all possible information.
When you use も, you are expanding your focus to include an additional thing. This may be a surprise addition to the mix considering that the typical “what is the difference between…” will rarely if ever mention it, but I feel it’s worth including. In some sense, も can be thought of as the “anti-は”. Whereas は limits the focus of the topic, も expands that focus; while は excludes things from its focus, も maintains the current focus while also introducing something else, or implies that, in addition to the specified thing, other things are also relevant.
Now that we have a simple rubric established for each of our particles, let’s run some comparisons to get a feel for the specific nuance in practice.
As I mentioned above, when talking about things you like, you’ll almost always use が. However, there are situations where は can be appropriate. Consider the following scenario:
A: はい、いちごミルク Here you go, strawberry milk B: えー、いやだよ Ehhh, I don't like that A: あら？いちごが好きだって言ったんじゃないの？ Huh? You said you like strawberries, didn't you? B: いちごは好きだけど、いちごミルクはちょっと… I do like strawberries, but strawberry milk is...
Why does B use は in the final line? Because the implication is that while she does like strawberries, that’s all she likes — strawberry-flavored milk is not included. Of course she isn’t saying that strawberries are literally the only thing she likes; she’s simply limiting the scope and implicitly saying that, when it comes to strawberries, nothing else but the real deal– including the milk her friend bought her — is included.
気がする (to get a sense that…) is another pattern where you’ll usually see が, and the reasoning is pretty clear if we stick to our rubric from above; you’re pointing out the thing (in particular) that you noticed, and don’t usually need to make any special contrast, so you use the neutral が.
However, は is valid here as well; it just means something different. Let’s look at an example from Persona 4, where Yukiko is relating her hazy memories from the day she was kidnapped.
ただ、玄関の…チャイムが鳴って、 I have the feeling that the doorbell rang, 誰かに呼ばれたような気は、する and someone called my name, but...
Why は instead of が? Because this is the only thing she remembers. Upon answering the doorbell, she had a chloroform-soaked cloth pressed to her mouth and lost consciousness immediately. The fact that someone called to her isn’t something in particular that she noticed, it’s the extent of what she noticed.
A common beginner tactic is to take a sentence with some difficult particle, swap it out for another particle, and ask what the difference is. Honestly, please don’t do this. More often than not, one of the two options ends up being complete nonsense, and は・が are especially susceptible to this due to the way they interact with question words.
For example, take the following two (near-identical) sentences. How might changing the particle change the meaning of each one?
It’s a trick question, actually. The answer is “the second one is completely ungrammatical”, and here’s why:
- A question word can never be followed by は
- A question word can never be preceded by が
Note: There are a few exceptions to these rules, such as なにはともあれ; however, these are fixed expressions based on archaic forms which are no longer relevant in modern Japanese.
These restrictions are again consistent with our rubric from above. Let’s look at some well-formed examples instead:
When a question word is followed by が, we’re trying to identify the information that fits in that slot. In #1, we want to identify who the teacher is, so we use が.
When a question word is preceded by は, we’re limiting the scope of how that question can be answered. In #2, we want to limit answers to being about “teacher”, so we use は.
While it can be difficult to choose between は and が at first, at least when it comes to asking questions there’s just one consistent rule.
There are a few uses of は which are often taught as being distinct from the “topic particle”, but I think they fit perfectly within the “limiting” meaning we’ve discussed so far.
Emphasizing (small) amounts
When it comes after a number or counter word, は has the function of expressing that that number is all there is. For example:
アプリで、2回は会ったけど、3.4回目以降は仕事やら何やらで忙しいと理由をつけて約束しない Through the (dating) app, I met up with him twice (only), but from the third and fourth attempts onward, he would give excuses like "I'm busy with work", and wouldn't set a date.
Remember, counter words act adverbially. There’s no reason to use a particle here at all; ２回会った would have neutrally expressed “met two times”. Using は here isn’t as strong as using だけ, but it does add the nuance that the number is smaller than might be expected or desired.
When paired with くらい or だけ, は can also be used to express a bare minimum.
どうか、命だけはお助けください！ I beg of you, spare my life (if nothing else)! 緊張しちゃってたんだろう？忘れ物ぐらいはするさ You were nervous, right? It stands to reason you'd leave (at least one thing) behind.
Emphatic negative with は
(Verb stem) + は + しない is one way of forming a strong rhetorical negative, often translated as “there’s no way that…”. The same “limiting” function applies here as well.
僕の行く所なんて、どこにもありはしない There's no way that there's a place for me out there
A place for me? Even something as small as it simply existing is too much to ask for.
も can be used in a similar way to the two cases above, but with the opposite effect (expanding rather than limiting).
Emphasizing (large) amounts
When it comes after a number or counter word, も magnifies the importance of the number. Take this example from 青春ブタ野郎はバニーガール先輩の夢を見ない, when Mai guesses that Sakuta has no friends:
友達ならふたりもいますよ If we're talking about friends, I have two (a large amount) of them ふたりは『も』かしら？ Is two really "a large amount"?
To Sakuta, having even one true friend is more than enough, so two is a number worth being proud of.
Emphatic negative with も
(Verb stem) + も + しない is another negative form, but once again, も expands.
日本語は話せもしない I can't even speak Japanese
The implication here is that not only can I not speak Japanese, but I can’t read it either (or any number of other possibilities). With no prior explicit context, we’re left to speculate as to what the previous focus was.
Native Japanese speakers will use は and が intuitively, without even thinking about it. They will often struggle to explain the difference, but will usually be able to immediately identify a sentence which sounds unnatural due to the choice of particle. Furthermore, while choosing between them is often a matter of instinct rather than conscious thought, the nuances of each one are no mystery. The following clipping from ハイキュー is a great example of this.
A savvy reader will instantly pick up on the fact that this is the limiting use of は, here used by 月島 (the tallest member of the team) to tease 西谷 (the shortest) about the fact that his stomach is the only big thing about him. The thing I find really interesting here is that the は has a 傍点 (emphasis mark), which tells us that far from choosing this particle based on sheer instinct, the author went out of his way to show that it was chosen explicitly to get this particular meaning across.
I believe anyone can reach this same point, it just takes time and constant exposure to the language. Hopefully these rules can help kickstart you on your way.