As a former English teacher (and Special Ed, at that, so I'm not letting dyslexics off the hook that easily!), I second thatwindow's suggestion. I used to start each year by explaining to my high school classes that communication is all but impossible. When you speak face-to-face, the other person really only "gets" about 40 - 60% of what you're trying to convey because we all come from a different sphere of reality. Face-to-face you have hand gestures and expressions to help with interpretation. If you have a common vocabulary and good grammar, that's the best you can hope for.
On the phone the comprehension level drops to less than 30%. Minus the gestures and expressions, we have only common definitions of terms and basic grammar to rely on.
Written work communicates AT BEST about 15-20% of its meaning! And that's with correct spelling, grammar, punctuation, and a common database of vocabulary. Deduct any of those contributions, and you're down to virtually NO communcation and lots of misunderstandings and resulting conflicts.
SO . . . if you're not sure, keep your sentences short and put periods after each thought. Compound-complex sentences without punctuation can't be understood.
Here's the exercise I used with my classes every September:
Punctuate this statement correctly
THAT THAT IS IS THAT THAT IS NOT IS NOT IS THAT IT IT IS
