Hello Mad Jock! Well, here I am, sh!t hot at grammar and also knowing about Fourier and Laplace transforms! Seems I should earn somewhere between £5 an hour and £100k per annum. Actually, that's about right.
In my somwhat limited experience, I can usually tell the difference between typos, spelling mistakes, poor grammar due to bad education, dyslexic English and just plain bloody laziness. It is the last of these that gets up most people's noses, including mine!
Every dyslexic person I have met (only a few admittedly) has been able to converse in perfectly good English but has had difficulty with the written word. In some careers, this could be a problem but I doubt it would be in aviation. However, chips on shoulders can be an issue!
Cheers
Whirls