To be X vs To X (intransitive)


Was just wondering if there’s any reason why sometimes Wanikani doesn’t accept ‘to be X’ as a valid answer for intransitive verbs, for cases where it would be natural in English to use ‘to be X’.

E.g. To Break 折れる (intransitive)
Doesn’t allow “To be broken” as an answer, but I think it can mean “To be broken”


To be X isn’t always valid, but it often is. Feel free to add a synonym when you think it’s appropriate.


Sometimes I’m guessing it’s just a restriction of how many definitions they want to put or how loose they want to be, but sometimes it doesn’t make sense with how the word is presented.

For the case of 折れる, it means something breaks when the first person is not doing the breaking and is referring to point in time when X breaks. If your referencing it in it’s broken state, you would probably use ている form or a different verb.

Mostly it’s just small nitpicky things that come down to how particular you want to be. If you think the definition should be more general, add a synonym.

[edit] Link to a bunch of example sentences using 折れる in case that helps.


Yeah, in this case “to be broken” would probably be wrong since that would use the ている form. But “to become broken” might be a reasonable synonym. At that point “to break” is more natural, but sometimes adding synonyms just to clarify the meaning can be useful.


“to be X” is the passive form, which is does not always or generally comport the same meaning as a true intransitive form. The example you gave is a good one to show it: “to break” in English is actually two different verbs, one is transitive and one is intransitive. They just happen to have the same spelling. The difference is:

Someone breaks the window. (transitive)
The window breaks. (intransitive)

contrast this to:
The window is broken. (passive [with to be])

Since in English, the passive form can only be made from the transitive verb (where the object becomes the subject of the passive sentence), in your case the translation “to be broken” would actually refer to to transitive verb - and that would be wrong.

Again, contrast the two meanings:
The window is broken.
The window breaks.

They are clearly different. But even if you account for the difference in the temporal sense:
(A) The window is in the process of being broken.
(B) The window is in the process of breaking.

When would you say (A) and when would you say (B)?
Would you rather say A or B when you’re talking about a spaceship window being hit by a mini meteorite? It’d prefer B.

Would you rather say A or B when your’re talking about a closed store with valuables in it at night? Here, A would be prefered.
This is because even though it is passive, it strongly hints to someone doing the breaking, even if you don’t know at all who it is; whereas (B) does imply that there is no agent behind it.


I had a whole answer for you, but dadadavid hit literally every point, so … glares



As a rule of thumb, when you find an transitive/intransitive pair, rather than thinking of the intransitive as the passive of the transitive, I find it’s usually more helpful to think of the transitive as the causative of the intransitive, e.g. 折るing something causes it to 折れる. ‘Break’ can be both transitive and intransitive in English, but we can still think of the transitive version as meaning “to cause to break”. Another example would be 流す, which WK lists as “to flow” but really means “to cause to flow” because it’s the transitive counterpart of 流れる.

This is called the lexical causative (because the causative sense is “baked into” the dictionary form of the word), as opposed to the morphological causative (changing the word, i.e. the ~せる/~させる form), or the periphrastic causative (adding words, i.e. the ~てもらう form).


Ahh, thank you so much everyone for your explanations; that makes a lot of sense.

@dadadavid The idea that passive can have an implied agent was new to me, but I can see how in contrast to intransitive verbs it can have this nuance to some extent.

@thegooseking You’re right, I need to be careful not to assume passive=intransitive. Thinking of it that way may be the best way to go. By the way, do lexical, morphological and periphrastic causatives all have the same meaning, but achieved via different grammar structures? I know てもらう has the nuance of politeness; and I think it also has the nuance that the thing your acting on is sentient. You’re politely causing someone to do something. What about せる・させる?


Yes, from what I understand the morphological causative is usually used when the causer has “natural authority” over the causee (e.g. a teacher making a student do something), but when it’s used without that authority, it has a strong sense of coercion (e.g. a student forcing a teacher to do something). To avoid that sense of coercion, it’s better to use the periphrastic, which is why the periphrastic is considered more polite. By the way, you should take care that ~てもらう is not always causative. It just means that the agent does something that benefits the patient. If the impulse to do that thing came from the patient (e.g. if the patient asked the agent to do it), then it’s causative, but if the agent decided to do it on their own, then it’s passive.

The lexical causative can only be causative in the sense of physically manipulating something (i.e. “direct” causative). The morphological (~せる/~させる) can be causative in a much larger number of ways. The morphological causative can be:

  • physically manipulative (and if you’re manipulating a person, that manipulation can either be assistive - helping someone do something, e.g. 母親が赤ちゃんを歩かせた - “The mother helped the baby to walk”, or coercive - making someone do something)
  • directive (either telling someone to do something or allowing them to do it; needless to say, this only applies to sentient causees)
  • non-interventive (causing/allowing something to happen by inaction)
  • adversative (a little more complicated, this is somewhat similar to the “suffering passive” where someone is psychologically adversely affected by an event; to “have someone do” something that the subject didn’t want them to do, e.g. あのかわいそうな男が奥さんを死なせた - “That poor man had his wife die on him”)

Although the morphological causative can express physical manipulation, it’s only generally used for that when a lexical causative is unavailable, or else when you’re manipulating something in an unusual way. The example my book gives involves stopping an engine with a key:

  • キーでエンジンを止めた (lexical) - I stopped the engine with the key (I turned the key in the ignition, and the engine stopped)
  • キーでエンジンを止まらせた (morphological) - I stopped the engine with the key (I threw the key into the engine, causing it to jam)


May I inquire about the book? That’s such gold right there. I mean I was kinda aware of these different forms of the morphological causative but having them spelled out like that can make things much clearer than working with a “gut feeling” of how to interpret it :smiley:.


The book I’m getting this from is more linguistics-focused than practical-Japanese-focused. Which is to say it goes into a lot of technical detail and doesn’t leave things oversimplified. Oh, and of course it uses rōmaji, because linguistics. It’s by Shoichi Iwasaki (UCLA Professor Emeritus in Asian Languages and Culture) and it’s called ‘London Oriental and African Language Library #17: Japanese’ (or just ‘Japanese’).


I’m pretty sure I have this same book and it’s sheer gold.


Sounds it. Does someone have the ISBN?


Yep, it’s ISBN-978-90-272-3818-4.


And a link to its press page:


@thegooseking & @konekush - Thanks, both.