This is the first time and also the last time I’m going to tell you this, so make sure you’re listening. Write it down in case you’ll forget.

“Definitely” does not contain an “a”. It is not spelled “definately”.

If you value your life, you will never misspell it in my company.
(And no, I haven’t seen this misspelling here yet. I just saw it on someone else’s site and felt it was my duty to speak up. I’ve been silent for too long. And now I must be heard!)