I’ve always been a native English speaker, but my first 11 years of education weren’t in the U.S. I also don’t have an issue with: their, there, and they’re.

Affect and effect were tough for me, though. I still have to think about it for a moment

And slightly off topic, I still can’t tell the difference between pansexual and bisexual. Each time I feel like I have a decent internal definition someone comes along to inform me that I’ve got it wrong