英语介词until（till）即使不是在人类所有语言也至少是最普遍的十几种语言中非常独特的词：它具有一种语义上的状态反转。以下是我在Facebook语言学群中发的帖：
English "until"/"till" has a side effect of reversing the state. For example:
"The scientists had not found a solution to the problem until 1970."
(informally, "did not find")
It implies that the solution *was* found in 1970. I don't know if there's a linguistic term to describe this state reversal. But in many other languages (probably Spanish, German, Chinese, Hindi, Persian, etc.), the word generally translated as English "until" does not seem to have this implication. This lack affects the English writing of the people speaking those languages natively. For example, a Persian scientist wrote (mcijournal.com/article-1-62-en.pdf):
"Microgravity has different effects on normal and cancer cells, but the related mechanisms are not well-known till now."
He didn't mean to say the mechanisms are (finally) well known now; by "till now", he meant "so far" or "even as of today", a continuation of the state of "are not well known".
This implied reversal of state of English "until" seems to be more obvious if the sentence is negative.
I'd like to know
(1) whether there's a linguistic term for this semantic reversal of state implied by English "until";
(2) whether it's correct to list Spanish, German, Chinese, Hindi, Persian as the languages (maybe all languages except English?) in which a simple equivalent of English "until" does not have this semantic reversal.
(见facebook.com/groups/generallinguistics/permalink/10157494708249346/及讨论)
在此我提出这句英语
"The scientists had not found a solution to the problem until 1970."
暗示科学家们终于在1970年找到了对这个问题的解决方法，而该语句的西班牙语、德语、汉语、印地语、波斯语的直译不具有这个隐含意义。比如汉语“科学家们直到1970年没有找到对这个问题的解决方法”，一般会被理解为1970年仍然没有找到，即这个没有找到的状态持续存在，但在英语中却从没有找到反转为找到。该Facebook群的成员来自世界各地，大多数是语言学学者或学生，整个群能读懂的语言估计至少有二三十种吧，没有人对我列出的几种语言提出实质性的异议，还有人补充缺乏这种状态反转的语言，例如有人指出意大利语等。至于是否语言学中有无术语描述我暂命名为semantic reversal of state的现象，多人提出几个概念（presupposition、telicity等），但我认为都不能完全符合。因此，我暂时得出结论：英语的until或till是人类语言中罕见或唯一具有语义的状态反转属性的用于表达时间延续到某点的介词。
（顺便说一句，我与那位讲波斯语的伊朗生物学家email联系，确证了他本来的确是想说“the related mechanisms are not well known so far”。）
