I'm a lexicographer.

I make dictionaries.

And my job as a lexicographer

is to try to put all the words

possible into the dictionary

My job is not to decide what a word is

that is your job

everybody who speaks english

decides together what's a word and 
what's not a word

every language is just a group of people

who agree to understand each other

now sometimes when people

are trying to decide if a word is good
or bad

they don't really have a good reason

they say something like,

"because, grammar!"

(Laughter).

and i don't actually care 
about grammar too much

don't tell anyone

but the word grammar--

actually, there are two kinds of grammar

there's the kind of grammar that kind of lives 
inside your brain

if you're a native speaker of a language or a good speaker of a language

it's the unconscious rules that you follow

when you speak that language

and this is what you learn

when you learn an language as a child

here's an example

this is a wog

right, it's a wug

Now there is another one

there are two of these

there are two

(audience): wugs

exactly!
you know how to make

the plural of wug

that rule lives in your brain

you never had to be taught this rule

you just understand it

this is a experiment that was invented

by a professor

at boston college

named jean burco0gleesin

back in 1958

so we've been talking about this for a long time

now these kinds of natural

rules that exist in your brain

there's not like traffic laws

there more like laws of nature

and nobody has to remind you to obey

a law of nature, right?

when you leave the house in the morning

your mom doesn't say,

"hey honey, it's going to be cold

take a hoodie, don't forget
to obey the law of gravity"

no body says this

laughter

now there are other rules

that are more about manners than they are about nature

so you can think of like

a word is like a hat

once you know how hats work

nobody has to tell you

don't wear hats on your feet

what they have to tell you is

can you wear hats inside

who gets to wear a hat

what are the kinds of hats you get to wear

those are more of the second kind of grammar

that linguists often call usage

as opposed togrammar

now, sometimes people use

this kind of rules-based grammar

to discourage people from

making up words

and i think that is, well, stupid

so for example,

people are always telling you,

"be creative, make music

do art, invent things

science and technology"

but when it comes to words,

they're like

"don't!"