Who/What decides if a word is "proper" English?

I was taught since kindergarten that "ain't" isn't a proper English word.

I was wondering, who determines which words are acceptable and which words are not? Do words ever go from "improper" to acceptable? What are some examples and what caused the change?

Solution 1:

The evolution of a language is the result of human interaction and socio-cultural changes over time.

Pop culture of various generations play on the kind of language we use. The people of the 1900s would not have envisioned that 'google' would become a standard word, although having just one function: an action of searching up on google.com. Such is the proliferation of the Google phenomenon within our generation's culture that is clearly shown by this.

It's like an internet meme; change starts in a small way in small communities, and spreads to others who have not heard of it, through word of mouth, or by themselves experiencing it. Through this way, it spreads and once it really catches on, it becomes a viral phenomenon. So, like English, words (and even how they are pronounced) are not decided by a few professors in a secluded enclave somewhere on this earth. Collectively, the entire English-speaking world (or in other words, all of us!) decide the rules. If a way of doing things catches on, they eventually become the convention, and if we feel that a certain way we have been doing things for a very long time is not in need for change, then it remain the way it is.

Solution 2:

Putting aside "dead" languages such as Latin, all others do actually evolve. At any given time a broad swathe of words / constructs fall somewhere between the two extremes of "definitely bad English" on one side, and "well-formed and appropriate" on the other.

An element may drift out or into of that middle band to or from either extreme, possibly repeatedly. Normally, no individual or organisation exerts much influence on most of this drift.

To put it briefly, nobody determines what's acceptable. But whatever most of us endorse individually gradually tends to become the publicised "standard".

Solution 3:

Democracy - it becomes correct through use.
"To boldly go" is wrong if you believe latin word order should apply to English but is now much more common and popular than "To go boldly"

I suspect "To be or not to be" was once frowned on