Translation:I only got off work at 11 last night.
I would be very interested to hear in which countries you think the phrase "I only got off" is "perfectly natural English." It's certainly not American English. In American English we would only ever say "I only" if there was a "because X." For example, "I only got off at 11 last night because someone else came in early."
"I only got off" is not a natural phrase on it's own just like "get off until" isn't. The construction is to do with the "only" before the action and the time. It seems you are admitting you are only exposed to one variety of English. There's nothing wrong with that. Here in Australia both are natural. I assume the same is true for the UK and elsewhere but I'm not an expert so I leave that to people from those places.
It is. Word for word it's essentially "I yesterday evening eleven o'clock only then got off work".
("O'clock" isn't really explicit; "十一点" is more like "at the mark of eleven": "I yesterday evening eleven mark only then got off work".)
Supporting your contention that the English is fine, Oxford says that "only" can be synonymous with "not until":
5. not until
We only got here yesterday.
And Merriam-Webster and Dictionary.com have the following entries:
4. a. : as recently as : not before // only last week
// only in the last year did she get recognition
7. no more or no greater than: we met only an hour ago
These definitions of "only" fit with how "才" is defined and used.
Wiktionary gives the following definition of "才":
3. only after; only then; not ... until
Here's the Chinese-English entry in Collins, which has supporting translation examples:
4. (程度低) only
⇒ 他才学会上网。 (Tā cái xuéhuì shàngwǎng.) He has only just learned how to use the Internet.
Other comments here suggest a lack of understanding of how "only" is used in the sense intended by Duo. Concerns about the misplaced modifier aside, adding a subordinate "because" clause is irrelevant, because it introduces a different context not present without it.
While the idiom probably trumps the explanation, it may be helpful to think about it not as meaning working later than expected (except perhaps incidentally), but about finishing work a somehow remarkable and relatively short amount of time before some other time or event (e.g. before the utterance of the sentence). I explain this further here:
It's not a good or natural translation of the Chinese, because "only" has many meanings and none of them inherently mean an action happened later than expected.
Even the dictionary, shows 才 being translated with "not until" instead of "only."
"I only got off work at 11 last night because my manager let me leave early."
The fact that the sentence can be modified to mean leaving early instead of late should make it obvious that it is not worded correctly.
When "not until" and "only" modify a time, they should be used before the time and not the verb.
I didn't get off work until 11...
I got off work only at 11...
Duo's sentence is wrong. While a dictionary can teach you definitions, it does not teach you where to properly place words in a sentence for each possible meaning. The Chinese 才 has the meaning of "not until."
It seems intuitive to me, particularly given the "才" in the Chinese.
What's intuitive is often subjective, of course, and others may disagree, but here's some dictionary support:
5. not until
We only got here yesterday.
Now let's imagine changing that to "We only got here last night at eleven." And then, with another substitution, to "I only got off work last night at eleven."
That seems quite natural to me, and it fits with how "才" is used, as demonstrated in the examples in this dictionary entry:
I think education level and location factor into whether some people think this phrase sounds natural. The official phrase poorly uses "only" to express working late. Most people in the US would just say "had" to make it clear they worked until a certain time and it was undesirable.
Natural (implicit lateness):
"I had to work until 11 last night."
"I didn't get off work until 11 last night."
Natural (explicit lateness):
"I had to work late until 11 last night."
"I worked late and didn't get off until 11 last night."
With this comment and your other in response to feyMorgana, you seem not to have understood how "only" is used in the intended sense (and to have ignored my English dictionary examples).
This is probably a case where the idiom trumps the explanation, but to understand the sense, it may be helpful to think of it not as being about working later than expected per se (except incidentally), but about finishing work a somehow remarkable and relatively short amount of time before some other time or event (e.g. the time of the utterance). In other words, "only" suggests the relatively meager thing we're left with.
On a similar note, Wiktionary provides the following definition of and example for "only":
3. As recently as.
He left only moments ago.
In general, "only" emphasizes the diﬀerence between possibility, presumption, expectation, or ideality on one hand and a lesser reality on the other, with the implied meaning being something like "while it might have been possible, expected, or better in some way for me to have ﬁnished work longer ago (and with more time available afterwards), in fact it was only at (or not until) 11 that I actually got oﬀ". The cleft structure, "it was only at 11 that...", demonstrates this a little more clearly, but in any event, Duo's use of "only" mirrors the meaning of " 才" quite well.
And it's not "poor" usage, or uneducated. On the contrary, the anecdotal evidence on this page suggests that better educated and better traveled speakers are likely to understand or accept it.
Edit (in response to your further comment below):
While I have some sympathy for style considerations (and I've already briefly discussed the misplaced-modifier phenomenon here), you appear to be trying to turn a personal (and perhaps regional) preference into a general rule, and apparently you don't trust Oxford, which is practically synonymous with "English dictionary". In particular, you haven't dealt with this, which is the very same structure:
5. not until
We only got here yesterday.
In any event, I'm content to stick with my own well-considered, native-speaking, dictionary-supported sense of it.
It's not about working later than expected per se
You are entirely wrong. The Chinese 才 is 100% about an action happening later than expected. It stated exactly that in the tips section.
To say that something happened later than expected, say 才 (cái, only) after the time and before the verb. https://www.duolingo.com/skill/zs/Invitation-2/tips
I'm a huge fan of Collins' dictionary which is UK based. I trust their translations and their examples.
It was not until 11 last night that I finished working.
It was only at 11 last night that I finished working.
Those are well written and naturally phrased sentences that show how "not until" and "only" can be interchangeable.
"I only got off work at 11 last night" is not naturally phrased. The word selection and arrangement make for a poor sentence and a poor translation.
It is understandable that a non-native English speaker would advise that 才should be translated as "only." However, the educated people who work for Collins disagree.
Knowing how to quote a definition and knowing where words should be placed in a sentence are two very different things.
There's a mistake in one of the proposed correct answers: I submitted "I didn't get off work until 11 pm yesterday evening", which IS correct, but which was flagged incorrect. The proposed correct answer was: "I didn't get off work until 11 pm *yesterday night." This is wrong. We do not say "yesterday night" in English - that is very unnatural. We say "last night" or "yesterday evening".
No, 才 here is best understood as "not until" http://dictionary.reverso.net/chinese-english/%E6%89%8D 昨天晚上 indicates the time frame.
Certainly. While it's more common to put "only" before the verb, there it can technically suggest that getting off work was the only thing you did at eleven, whereas your sentence (which sounds completely natural to me) more clearly states that it was only at 11 that you got off work.
Many would consider Duo's structure to be an example of misplacement of the modifier, though it happens to be how most people construct sentences with "only".
Your word-for-word translation is right. It's the sentence context that changes it. If you're just looking at single word translations, 晚上 =evening. 夜里=night. However, I don't know any English speaker who would call 11pm "evening." Where I'm from (US), 11pm is definitely "night." However, Chinese speakers use 夜里 a lot less often and for a more restricted timeframe than English speakers use "night." When I asked my Chinese teacher about this, she said that 夜里 sounds "spooky," similar to saying "in the middle of the night" or "in the dead of night" in English. So Chinese speakers will use 晚上 to describe later times than English speakers would use "evening."
I agree with most of you, this translation is a bit strange.
I'm not fluent yet (which is why I'm using Duolingo, so please correct me if I'm mistaken), but I have taken some Chinese classes at a university, and I leaned how to use 才 there. My teacher told us that 才 bears a strong resemblance to "not ... until" in English. Even though a direct translation between "才" and "not until" makes English sentences a bit clunky, it usually conveys the meaning of the sentence more effectively than translating "才" into "only".
Here are three instances where 才 is used in a sentence (I wrote the first two):
你昨天三点才吃午饭了。-> You did NOT eat lunch UNTIL 3 o'clock in the afternoon yesterday.
他每天十一点才回家。-> Every day, he does NOT come home UNTIL 11 o'clock.
他才学会上网。-> He did NOT learn how to use the Internet UNTIL [just now]
Here's an entry for 才 on Collins Dictionary if that helps: https://www.collinsdictionary.com/dictionary/chinese-english/%E6%89%8D