Whether you land up in China, Finland, Brazil or Rwanda, there's a good chance OK is a word people would understand. Indeed, OK is the most widely understood word on Earth - the closest we can get to a universal word.

<center>https://upload.wikimedia.org/wikipedia/commons/1/19/OK_Sign.jpg</center>

### But how did it begin?

Firstly, OK is indeed an English word, though one that is heavily loaned to other languages. 

Etymologists prefer the Boston fad theory, one which has a fair amount of evidence gathered by etymologist Allen Walker Read. There are hundreds of other hypotheses, though. 

In the late 1830s, Bostonians passed their time making up abbreviations for all kinds of expressions. It was the playground of newspaper editors, but the public joined in the fun as well. At the same time, there was another fad spreading across the USA where people comically misspelled words for fun.

Yeah, things weren't so interesting before TV, movies or internet. Indeed, words were the primary and easiest form of consumption. This is evident in literature of the time - there's a lot of play on form of the language rather than content. That said, our ROFLMAOs and OMGs are pretty similar...

Back to the US, a funny misspelling was "oll wright" for "all right". Back in Boston, this was promptly abbreviated to OW. Similarly, "all correct" got both the misspelling treatment to "oll korrect" and then the abbreviation to OK. 

### Prominence 

Of course, most of these misspellings and abbreviations were temporary fads lost to history. But OK exploded into global prominence. 

No one really knows how, and this one's a bit of a stretch with missing evidence. But it's the best hypothesis we have thus far. 

The misspelling fad and the abbreviation fad aligned with another co-incidence that then President, Martin Van Buren, was nicknamed "Old Kinderhook", after his birthplace Kinderhook. That was promptly abbreviated to OK. 

Van Buren stood for re-election during the 1840 Presidential election, and the phrase "Vote for OK" saw widespread, though not universal, adoption. 

Those two letters "OK" were now part of the American culture. How that was associated with the original oll korrect / all correct meaning, no one really knows. Certainly, there was pent up demand for such a word! 

From there, world wars, global colonisation and being a very simple word ensured the whole world caught on. 

### Variations of OK

Perhaps the most popular alternative hypothesis comes from the Choctaw (Native American) word "okeh". It's a stronger form of OK - "it is so and in no other way" - but ultimately a similar meaning to OK. 

Some cultures use OK as a positive, some as affirmative, some to acknowledge, while others to denote mediocrity. You have "K" and the "OK sign". Yet, it rarely leads to much miscommunication despite the variations. My two favourite variations are South East Asians who love to suffix OK. Of course, different cultures within SEA have different suffixes meaning different things. E.g. OK-lah, OK lang etc. Indians love to use it as a question, to mean "understood?". Funnily, it's also used as the answer - "Better behave yourself, OK?" - "OK"!

You'll never guess the second most understood word though!

Further reading:
http://www.jstor.org/stable/453580?seq=1#page_scan_tab_contents
https://en.wikipedia.org/wiki/OK
http://www.bbc.com/news/magazine-12503686
http://www.miketodd.net/encyc/okay.htm
https://web.archive.org/web/20101224185657/http://www.illinoisprairie.info/chocokeh.htm
https://en.oxforddictionaries.com/explore/what-is-the-origin-of-the-word-ok