Everyone knows how good they are. 😛 On a scale of 1 to 10, how good would you say your grammar and spelling is? Personally, I'd give myself a 7. My grammar is good, but not great.
It just depends for me. In casual conversation, I'm probably a 6 or 7 out of 10, but when I edit, I can probably get things up to 9 out of 10. I have a good amount of experience editing and critiquing writing, so I'm pretty good at catching most errors. I've also been working on improving my style a bit lately, since writing is one of my hobbies. I purchased a copy of the Chicago Manual of Style the other day. Pretty good reference, though very long!
Possibly a 6 or 7 most of the time, unless it involves writing an important document for my school or job then that rating gets an immediate bump to 9. I'm involved in a department with overwhelmingly strict writing guidelines.
I don't think it's ever reaching 10 as my unusual passion for writing keeps me from ever being content with my work.
I spent majority of my life glued to a wide variety of exceptional books, and I'd say I learned English solely off them. I didn't actually get into English classes until university started.
...aaaah I can remember how awful my grammar was way back in 2002 when I first started posting in forum threads...
I started improving after having read many posts, and then shortly after that books written in English invaded my life.
I kind of feel the benefits of my vocabulary built from reading. Somehow it gifts you with the ability to detect people who abuse their thesaurus to make up for their lack of vocabulary easier, because they miss the subtle differences between the synonyms when they replace their simple composition with seemingly exotic words in an attempt to sound clever or convincing. It's not something you actually point out specifically, but it's indubitably interesting to encounter in everyday writings.
If I had to score myself, I'd give myself a seven out of ten as well. I mean, I'm not great with grammar. That said, I do try very hard and constantly work towards being better. Spelling wise, I feel like I'm pretty solid.