I’ve previously written about some of the grammar rules in Early Modern English. An obvious question: why did it change?
Lots of research goes into explaining such changes. But the answer to this question is often we don’t know. People started saying stuff differently. It’s like asking why genetic drift happened in an evolutionary lineage. It happens all the time and it’s effectively random.
I’ve noticed some usages arise from people trying to sound silly. Some examples:
When I was very young, it would be considered ungrammatical to say because reasons. You had to say because of reasons. That is, because was a preposition1 that could only take either a standalone clause or a prepositional phrase beginning with of as its complement. This is still the case in most formal written English, but the new usage has spread far enough that I predict it’s here to stay. Now because can take numerous things as its complement: nouns, adjectives, interjections, lots of stuff.
When using a verbed word, people will sometimes choose to use an adjective rather than an adverb. This is especially true of good vs. well. Ex: I don’t adult good. But it can be used with other adjectives. This one is less common, but I’ve seen it around.
Normally when verbing, you take a noun or adjective and use it as a verb with zero change in the word. Ex: I’m trying to adult. A verbed word follows the standard rules of conjugation: I adult, she adults, we’re adulting. But people sometimes take a word that’s clearly been verbed and don’t conjugate to the present participle where it would be expected. Ex: I’m bad at adult (with the meaning I’m bad at adulting, which itself has the meaning I’m bad at being an adult.)
A related usage is to use a noun as expected, but to leave it singular and without a determiner, when a plural or a determiner would be expected. See this classic example:
These all have something in common: They sound childish, like the kind of mistakes a 3 or 4 year old would make. Their usage tends to be relegated to specific circumstances.
The speaker is trying to sound stupid.
The speaker is attributing imaginary dialogue to someone else and trying to make them sound stupid.
The speaker is trying to imply that something is so obvious or fundamental that even a 3 year old should understand.
The speaker is trying to take on a generally ironic tone.
In other words, they’re usages associated with being a smartass.
I wonder how much fundamental, permanent usage changes are driven by such smartassery. Children often don’t understand irony, let alone ironic language usage. Maybe they hear stuff like this and think it’s standard English?
I don’t know about the latter 3 usages, but because X is now extremely common. I think it’d still be categorized as slang, but that won’t last forever. I’ve seen it in a fragment of a book written by a PhD in her 70s.
A common story for how English lost thee and thou has to do with rising social mobility. You used to have two usages: as second person plural, and as a singular deferential pronoun used to refer to someone above your class. Children also used it for their parents. The story goes that social mobility made it confusing when one or the other should be expected. And people got offended by thou, so why not just use you for everyone?
But I’m not ready to rule out the hypothesis that smartass teenagers went around calling people you sarcastically, to make fun of the status-obsessed adults.
1 Contra many dictionaries and language guides, but I agree with Pullum about this.