Learning to communicate effectively is highly important so that you don't make yourself, and by extension, your company, look stupid. That said, I probably used too many commas in that last sentence. Their our alot of common mistakes that people make to often that could of easily been avoided. In the case of Adam V.'s coworker (who we'll call Angie), though, her mastery of grammar worked against her.
In a frantic email, Angie asked Adam "What's wrong with my program? I can't figure out why it won't complile!" Adam stopped by her desk to have a look and found the line that was causing the build to fail.
printf("The result is %d," value);
It was obvious to Adam that the comma and end quote signs should be swapped.
"See," Adam explained, "the comma is used to separate function parameters. Your first parameter is this string here, and then the second parameter is this variable called 'value.'" Adam's strengths lie in C++ syntax.
"Yeah, I know," replied Angie. "But I'm using it right — the comma is supposed to go inside the quotes!" Angie's strengths lie in English syntax.
Sadly, it would seem that Angie never managed to reconcile all of the differences between English and C++ and was let go less than a year later.