OK!

The BBC recently published an article explaining the origin and history of 'OK,' as explained from an author who recently wrote a book on it.

Some of the article is informative:

But what makes OK so useful that we incorporate it into so many conversations? It's not that it was needed to "fill a gap" in any language. Before 1839, English speakers had "yes", "good", "fine", "excellent", "satisfactory", and "all right".What OK provided that the others did not was neutrality, a way to affirm or to express agreement without having to offer an opinion. 

Some, not as much:

Visually, OK pairs the completely round O with the completely straight lines of K. 

Speaking of books, I have finished 2/3 and both in time for book club! Green Metropolis was awful, just don't read it. On the other hand, despite a slow start, Great Expectations was lovely. On to the Immortal Life of Henrietta Lacks...