If you could rescind one rule of grammar, what would it be?

It is perfectly okay to split an infinitive: that is, the sentence "not to like someone" means something QUITE different from " to not like someone". But the second one is a split infinitive ('not' comes between 'to' and 'like') so the sentence is returned to something that has a completely different meaning. For example, I don't like people I've never met. How could I? I've never met them. But I don't DISLIKE them. To not like someone means to dislike them.

Could has an "L" in it too, but people don't get upset about that being silent.

I'd definitely do away with not starting a sentences with a preposition. In most cases it's no problem, but there are those few, and they're almost impossible to explain to children.

Oh yeah, I'd probably do away with so many homonyms. Most people get them wrong and it makes me crazy. I can't help but correct people. I corrected a lease once, as I was signing it. My friend was sitting beside me, and she saw me staring at "your" that should have been "you're" and she said, "Don't do it. Just let it go." But I couldn't. I'm obsessive about it. :(

Well, it's not a writing rule but a speaking rule. But I would do away with having to pronounce salmon "sammon". Well personally I don't let that rule affect me but I hate hearing other people pronounce it "sammon". It has an L in it!

Use of the apostrophe for all possessives.

No one seems to understand or remember the rules.

(Above) Calm down. Do you pronounce the L in that too?

What about the silent 'p' in 'bathing'? (joke)