The fact that some people can't
distinguish the difference between etymology and entomology bugs me in ways I can’t put into words.
= new reply since forum marked as read
and 
... IMPLY and INFER are synonyms. Imply is to suggest; infer is to deduce. Two different words with two different meanings.
Or those that confuse HOMING and HONING. One does not HONE in on something, one HOMES in on it, as a homing pigeon always returns to its dovecote. One HONES a knife, and, hopefully, their grammatical skills.
And, of course, there's the perennial favorite, IRREGARDLESS, which is a double negative and NOT a real word.
Oh, and let's not forget ORIENTATE. One orients one's self, or undergoes an orientation. -ATION is a suffix. When you make a presentation, do you presentate it? God, I hope not. And no one who conversates is worth talking to.
Okay, I'll stop now. 
