Definitely... it's something I've struggled with my whole life, and is very frustrating. I'm well spoken and write well too, but there are times when I can't even get out the most simple thought, and I'll write something and it has the worst spelling and grammar...not to mention if it's handwritten, it looks like chicken scratch and even I have no idea what I was trying to write.
It happens a lot more when I'm very stressed or anxious or having a moment or what have you. It feels like my brain is fried and just refuses to operate like it should...the thoughts are in there, I just can't get them out. I mix up letters in words, words in sentences, use the completely wrong word in a sentence..not just written but when speaking as well. And I also will completely blank out on what word I want to use...something so basic like, I want breakfast for dinner...and I'll be stumped, and will have to say, you know that first meal you eat in a day? I want that, except for dinner. People have joked with me if Im sure English is my first language...I do feel like a dolt when that happens.
It was quirky and funny when I was younger, even though no one has ever questioned my intelligence, friends often said I'm like the lost cast member from the movie "Clueless"... but as I get older, it's gotten worse...I shudder to think where I'll be in another 10 years or so.