A respected friend and academic was speaking about something personal. I wish I could recall what it was but the only thing I can remember about the conversation is how incredibly often she used -- clearly without noticing -- the word "like". It was placeholder, punctuation, and security blanket in one. When this person wrote, I knew, it was clear, eloquent and incisive. When she spoke, she undermined every phrase with disqualifiers, fuzzy words and, of course, "like".
I couldn't help myself... I started counting. She used "like" 13 times in one single sentence. Hearing that broke something in my ability to flow with normal conversation and I began noticing similar things that I never had before. It quickly became apparent how important subtle (and not-so-subtle) communication patterns are in determining a speaker's credibility and impact. A few of these stand out more than the rest.