Over the last couple of years, as I’ve spent a lot of time reading Japanese literature and immersing myself in the language, I’ve become increasingly aware of a particular phenomenon which is endemic to the language at large; which can easily and precisely explain many seemingly unrelated mechanics; and which is so rarely mentioned that I didn’t even realize it had a name until I stumbled across it one day. The 内・外 dichotomy (“uchi/soto”; essentially translated as “inner/outer”) is, with only slight exaggeration, what I might consider in many ways to be a “unified theory of Japanese”. It forms a key component of both the language and the societal practices that define the culture at large, and by understanding it I believe it’s possible to form a deeper, more intuitive grasp of Japanese as a whole.

1. Laying the foundation
2. Forms of address
3. Here, there, and over there
4. Invitation and assertion
5. Coming and going
6. Giving and receiving

This article is a work in progress, and I may add new sections from time to time.

Laying the foundation

Let’s start by defining what exactly 内 and 外 mean — and to do this, we first must define 内, because 外 is only ever defined as “that which is not 内”. 内 is fluid and ever-changing, but it always retains its core meaning of “inside”.

• 内 can be you, yourself, one person and nobody else
• 内 can be your family or your household
• 内 can be your company, your division, or your team
• 内 can simply be the things within your realm of influence

As the definition of 内 changes, 外 responds in kind.

• If 内 is you, then 外 is everyone else
• If 内 is your family, 外 might specifically be the family of a friend
• if 内 is your company, perhaps 外 is one of your customers, or another company you do business with

Forms of address

This social dynamic is the basis for every seemingly complicated rule about the way the Japanese address each other. Polite, casual, respectful, humble, formal — all of these registers can be easily navigated simply by understanding the logic they all have in common.

For illustration, let’s take a look at a common question:

If I'm supposed to refer to my own father as 父, but someone else's father as お父さん, why is it that I so often hear people addressing their own fathers as お父さん?

The advice that leads to this confusion is no doubt well-intentioned but it’s an oversimplification that ultimately leads to more harm than good. Fortunately, 内・外 can be employed here to provide a clear rubric.

Firstly, it’s important to know that 父 is a humble word (i.e. it conveys deference to the listener), and お父さん is a respectful word (i.e. it conveys reverence to the listener). These two registers are of utmost importance in the very difficult 敬語 speech, which we won’t get into for now.

Now that we understand the registers of each possible word for “father”, 内・外 can give us the keys necessary to put that information to use.

• Use humble language when talking to 外 about 内
• Use respectful language when talking to 内 about 外

Applying these rules to the quoted advice above, the logic checks out:

• If I am talking to a friend about his father, I will use お父さん (respectful)
• If I’m talking to a friend about my father, I will use 父 (humble)
• If I’m talking to my father, I will use お父さん (respectful)

Aha! The missing link clicks into place. My father, while he may be 内 when I’m speaking to my friend (as a representative of my whole family), when I address him directly 内 is now only myself and 外 is everyone else, obviously including my father. As such the obvious move is to use respectful language, which means お父さん is the best option here. It would of course be very rude to address someone to their face with a humble term, after all.

The same logic can be applied to other less-common words such as 父上 or 父親, as well as words for other family members; the key in each case is whether the word is humble or respectful.

One special note: in casual conversation, it’s entirely normal to refer to one’s own parents as お父さん・お母さん etc without taking 内・外 into consideration. There’s no need to be humble when speaking on a peer basis; this could even be seen as standoffish and therefore rude. It’s a somewhat common trope in anime for a character — unused to public speaking or acting as a representative of their group — to accidentally say お母さん before self-correcting to 母 when giving a speech for the first time.

Here, there, and over there

The これ・それ・あれ words (and their compatriots like ここ・この and so on), are usually taught in the context of a conversation between two people. これ is “this” (something near the speaker); それ is “that” (something near the listener), and あれ is “that over there” (something distant from both parties).

Let’s take a look at a tried-and-true scenario which will be familiar to any student of Japanese: a pen sits on a desk, and by some miracle, I have never seen such a thing. I pose a question to you:

これは、何ですか？

それはペンです

An obvious question, and a common stumbling block, is “why do I use これ while my partner uses それ? Is it because I’m closer to the pen than he is? If we were both the same distance from the pen, would we both say これ?

In terms of oversimplifications, I can hardly fault the “near the speaker/listener” guideline. It took me a pretty long way without causing any major misunderstandings, and the nuances can be easily picked up through exposure. However, with the application of 内・外, we can do better. Here’s our new rubric:

• これ is for something in my 内
• それ is for something in my partner’s 内
• あれ is for something which is in 外 for both of us

With this new perspective, once more everything becomes clear. When I ask “what is this?”, I have metaphorically, if not physically, picked the pen up in my hand and started talking about it, and in so doing I shift the pen into my own 内 — not my family or my company, but my area of influence. To my partner, that pen is now strictly in 外 — it’s in my 内, so he uses それ to refer to it.

Furthermore, this vastly simplifies the matter of which word to use when referring to things which are not so easily grouped into “near the listener” and so forth. Imagine walking into a huge hangar in which a colossal robot is being constructed. 何よ、これ？ becomes the instantly obvious choice, even though certainly the whole room is not any nearer to you than to whomever you might be asking. This applies neatly to rhetorical questions as well, particularly when you might be alone with nobody to speak to; with no partner, there is no other 内, and as such the only options are これ and あれ.

Invitation and assertion

Since 内 is fluid, it stands to reason that it would occasionally change dynamically in the middle of conversation. Volitional speech is an excellent example of this case.

The immediately obvious difference between でしょう and だろう, two words used commonly to express speculation, is that the former is polite and the latter casual. This is a fine distinction to make, but it’s imperfect; there are cases in which でしょう will be more appropriate than だろう even if everyone involved in the conversation is part of the same friend group (ostensibly the same 内).

Let’s remember the rubric from the above section, where 内 = これ; specifically “the thing I’m currently thinking about”. In a scenario where you hold some opinion and would like others to adopt it too, what you ultimately want to do is expand your 内 such that your friends (or their current mental state) is now included therein.

• でしょう invites the listener to join you in your 内
• だろう expands your 内 to include the listener

Once again, polite form is used when 内 talks to 外 — and since でしょう merely extends an invitation, the boundaries have not changed yet. It is less presumptive than だろう, which effectively assumes that both you and your listener already share the same opinion, the same state of mind, the same これ or 内.

This same dynamic applies to volitional verb forms, like 行きましょう and 行こう; once again, the former is used much more often to suggest an action or invite others to participate. whereas the latter almost assumes that everyone will join in. It’s also worth pointing out that this “casual” form is the only form used for internal monologue, or in constructions like ようと思う or ようとする; when talking to yourself, there is obviously only 内.

Coming and going

Another topic which seems to cause a decent amount of confusion is the auxiliary verb pair ていく・てくる, which give a sort of “directionality” to other actions. Often these are glossed as “X and come” or “Y and go”, which works nicely for certain constructions; for example the idea of “bring” is expressed as 持ってくる (“take and come”); conversely “take away” is 持っていく (“take and go”).

Where this breaks down is when it comes to the more abstract uses of “to come” and “to go”. Take for example 見えてくる; this doesn’t mean “be visible and come” (indeed what would that mean exactly?) but rather “come to be visible”; something wasn’t visible before, but now it is. On the other side, consider the sentence 雲が移ろって、動いていく. While technically this sentence could perhaps be interpreted literally as “the clouds change, move, and go away”, some of the nuance is lost; a better translation would be “the clouds move along, ever changing.” This metaphorical directionality can be difficult for some students to grasp.

Fortunately, once again, 内・外 is the key. In both the physical and metaphorical usage of てくる・ていく, the direction being expressed has to do with a crossing of the boundary between the two domains.

• てくる has to do with coming from 外 into 内
• ていく has to do with going from 内 into 外

In the physical sense, 内 receives a new definition that we haven’t touched on in this article yet; it refers to where you are; your ここ as it were. When something moves into ここ, it uses てくる; when it moves out it uses ていく. This is all fairly self-evident.

In the metaphorical sense, 内 refers to what’s happening now. Consequently, 外 becomes what was happening before or what hasn’t happened yet. If we interpret the phrase 雨が降ってきた through this lens, we can see that the rain was (at one point) not falling, but now it is — and on the other side, 晴れていく means that the weather is beginning to clear up, and will likely proceed to do so. てくる shows us where we’ve come from; ていく shows us where we will go.

Giving and receiving

The question of when to use あげる vs くれる is yet another common point of confusion. Fortunately, this can also be explained rather easily with 内・外. Once again, the key piece of information here is the direction in which the boundaries are crossed.

• あげる is used when something is given from 内 into 外
• くれる is used when something is given from 外 into 内

One common mistake is to misunderstand くれる as a passive action that has to do with receiving (like もらう). This is not the case.

These words can be used both with respect to giving literal objects (used with nouns) as well as in terms of doing favors (used with verbs, in the form てあげる・てくれる). For the latter case, the thing being “given” can simply be thought of as the performance of the action; for example, 許してあげる would be “I will give you the gift of me forgiving you” (or more naturally “I will give you the gift of forgiveness”).

Helpfully, あげる can also mean “to raise”, which meshes nicely with the rules set in the forms of address section; remember, respectful speech treats things which are in your partner’s 内/your 外 as “elevated”.

With this terminology in place to help give us perspective, we can easily make sense of seemingly complicated constructions like 聞かないであげてくれ. At first glance the combination of あげる and くれる seems to make no sense, but in fact this is a common pattern that is used when making a request on behalf of another person. “Please, do me the favor (くれる) of doing her the favor (あげる) of not asking her about it.” In this case, “she” is a third party who is neither you nor your partner, and is therefore in 外 for both of you; hence あげる is the obvious choice for the first part of the request. From here, the performance of that part is being given from our 外 into 内, and so くれる used.