Ah I see, in this example the rule is "broken" because we know that "Sam" is the subject, but it can be interpreted as a grammatically correct, semantically meaningless sentence where "Reddit" is the subject instead.

I guess that makes sense, but I wouldn't say that both the grammar rule has been broken AND the result is a grammatically correct sentence; rather, it's one or the other. Either the grammar rule has been broken because the subject is in the wrong place, or the grammar rule has not been broken but the subject is such that the sentence becomes meaningless.

Sorry, I was confusing you with the commenter above who made the claim I'm referencing. I was curious about grammar rules that, when you break the rule, you still end up with a grammatically correct sentence that means something different from what you may have intended.

I'm still not sure why you referenced "colorless green ideas sleep furiously". It's a grammatically correct, semantically meaningless sentence but it doesn't appear to break any grammar rules, which is what I was originally asking for.

I've never suggested otherwise. You claimed there were many grammar rules which produce grammatically correct sentences when broken. I'm asking which rules those are.

What grammar rule does this sentence break? Isn't it grammatically correct, semantically nonsense?

“He will run yesterday” is grammatically correct? Grammatically speaking then, is this sentence future tense or past tense?

Is it grammatically correct for one clause to have two different tenses?

This isn’t merely semantically incorrect because it suggests the use of time travel, it’s grammatically incorrect because the verb is just conjugated incorrectly for the tense of the sentence.

As for your other examples, certain dialects have different grammar rules, but they’re still rules. Breaking grammar rules doesn’t usually produce sentences that are still grammatically correct but semantically different in this case either.

I agree. All four of the sentences you provided are grammatically correct and follow the grammar rule that the verb is conjugated to match the subject. What grammar rule has been “broken” that you would say actually produces a different, yet still grammatically correct sentenc?

A brown wall made of big bricks?

Can you name some grammar rules that produce grammatically correct, semantically incorrect statements when you misuse them?

For example “he are running” is not grammatically correct, nor is “he will run yesterday”. I can think of plenty of grammar rules that product grammatically incorrect sentences when not followed, so I’m a bit skeptical that there are many grammar rules that produce grammatically correct sentences when not followed