～ざるを得ない & やむを得ない
There are two fascinating grammar points which utilize the verb 得る in its sense of “to be able to” but in a negative context ～ざるを得ない and やむを得ない.
～ざるを得ない
～ざるを得ない derives from the kundoku1 rendition of 不得不 , which literally renders the meaning of this structure as “cannot do by not…” This is yet another instance in Japanese grammar of a double negative (二重否定), which in this instance does result in an absolute positive (超全部肯定).
As for the native etymology employed, ～ざる is the primary 連体形 of the classical negative auxiliary verb ～ず, and it accordingly attaches to the traditional 未然形 of verbs if there is to be any discrepancy due to modern innovations.
| Verb Class | 未然形 | ＋～ざるを得ない |
| 一段 | Stem + ∅ | 認めざるを得ない |
| 五段 | Stem + /a/ | 行かざるを得ない |
| サ変（する） | せ | せざるを得ない |
| カ変（来る） | こ | 来（こ）ざるを得ない |
The particle を, here, is traditionally viewed as being the case particle を2 marking the object of what cannot be done/attained. Though there is old-fashioned morphology utilized in this grammar pattern, it does get used quite often in the spoken language and written language.
As for how this grammar pattern translates into English, it is often translated as “to have no choice but to…” but it may also be translated as “to be compelled/obliged to…” Unlike similar grammar patterns like ～なければならない, ～ざるを得ない does not indicate that the agent (doer) ever had or has the intent of carrying out the action in question. In fact, there is a strong sense of reluctance and resignation. Also unlike ～なければならない, it can only be used with verbs of volition. It is also worth noting that the “agent” need not be the speaker.
1. 今季の結果を踏まえて大谷選手が世界一の野球選手だということを認めざるを得ない。
Based on the results of this season, (we) have no choice but to recognize that Ohtani is the best in the world.
2. 悪天候のため、我々はコンサートを中止せざるを得ませんでした。
There was no other choice but to call off the concert due to the weather.
3. パソコンが壊れたら、新しいのを買わざるを得ない。
If my PC breaks, I’ll have no choice but to buy a new one.
4. 口臭云々よりは歯の痛みで歯医者さんに行かざるを得ない状態です。
More so than mouth odor and so forth, it’s the tooth pain that has left me no choice but to go to the dentist.
5. 僕が引き受けざるを得ないじゃないか。
I guess I’m just going to be compelled to undertake it.
6. 外国に行くと、現地の人たちにとって自分が外国人であるということを意識せざるを得ない。
When you go to a foreign country, you are obliged to be conscious of the fact that you are a foreigner to the local people.
7a. 生徒が試験に失敗をすれば、教諭は責任を取らざるを得ない。
7b. 生徒が試験に失敗をすれば、教諭は責任を取らなければならない。
If the student fails an exam, the teacher has no choice but to take responsibility.
8. 社長からの命令なので、やらざるを得ません。
Since this is an order from the company president, I have no choice but to do it.
9. この問題はもう一度検討せざるを得ない。
We have no choice but to examine this problem one more time.
It is also worth noting that ～ざるを得ない may still be used with the passive form so long as the verb itself indicates volition, as the point of the grammar pattern itself is that the agent is compelled to do so, which contrasts with the essence of the verb involved.
10. 私の一番の恐怖、戦争が起きれば何もせずに殺されざるを得ないということだ。
My biggest fear is having to be killed from doing nothing if there were a war.
11. おでんは気温の高低に売れ行きが左右されざるを得ないものだ。
Oden is something whose sales are invariably controlled by the rise and fall of air temperature.
Although it may be tempting to attach negative adverbs like 何も or 全く to add a sense of “at all” to the sense of having to do something without the will to do so, these adverbs must agree with the negative element in the main clause, ～ざる encapsulates the verbal clause it is a part of into a subordinate clause, leaving 得ない as the predicate of the main clause, but no adverbial phrase of any sort can intervene between these two clauses. This problem is alleviated by using the grammar pattern ～ないわけにはいかない, which highlights a sense of responsibility to do something while also implying one’s reasoning for doing.
12a.「いまび」を勧められたからには、まったく読まないわけにはいかない。〇
12b. 「いまび」を勧められたからには、まったく読まざるを得ない。X
Given as how you have been suggested IMABI, you can’t afford not to read it.
In stiffer language, you may also see ～ざるを得まい, which uses the negative volitional auxiliary ～まい. This is generally not used in the spoken language.
13. 当然起こりうる現象と認めざるを得まい。
We are compelled to recognize it as a phenomenon capable of occurring naturally.
Orthography Note: A common misspelling of this grammar pattern by native speakers is ～ざる負えない.
やむを得ない
Meanwhile, the phrase やむを得ない derives from the kundoku rendition of 不得已, which literally renders the meaning of this structure as “cannot be stopped.” The verb やむ is the intransitive form of やめる, which can be seen used normally as in:
14. 雨がやんだ。
The rain has stopped.
Unlike ～ざるを得ない, やむを得ない is only used by the speaker to comment on the inevitable circumstance that is NOT pertaining to the speaker’s own actions. When translated into English, it is often rendered as “unavoidable/inevitable.” In the spoken language, it is usually replaced with phrases like 仕方がない.
Orthography Note: When spelled in Kanji, やむ is typically spelled as 已む in this grammar pattern, reflecting the Kanbun phrasing which brought it about. However, spelling it as 止む is not incorrect under the principle of simplifying its spelling to a common-use Kanji. It must also be noted that just as was the case before, this should never be spelled as やむ負えない.
15. 軍事的に劣勢だったので、やむを得なかったのだろう。
Since (they) were militarily inferior, (they) likely had no other choice.
16. やむを得ない理由のため、更新期間中に更新手続きをすることが困難な方は、その事実を証明する書面を提示する義務があるとご了承ください。
For those it may be difficult to go through the renewal process during the renewal people due to reasons which are unavoidable, (we) ask that you please acknowledge your responsibility to submit documentation proving that fact.
- Kundoku 訓読 refers to the process of rendering Kanbun 漢文 (Classical Chinese texts written by Japanese authors) directly into Japanese. ↩︎
- The case particle を also gave rise to a conjunctive particle rendition which is no longer used in Modern Japanese grammar. With this grammar point, it may arguably be interpreted as a bridging context between the case particle and conjunctive particle function of を, wherein [～ざる] may serve as a subordinate clause with [得ない] serving as the predicate of the main clause via its supplementary verb function with its head verb ellipsed, which would be the same verb as the dependent clause, thus rendering a literal translation of “while not doing X, X cannot be done.” However, because interpreting を as a case particle here requires no liberties in logic, this approach is not ultimately taken. ↩︎