Spelling

definitely

There is no A in definitely. There has never been an A in definitely.

  • definately

    definitely

    The middle is the word finite. No A anywhere in it.

The trick

The word finite is sitting in the middle of it: de-finite-ly. Finite means having limits, and it has no A. Neither does this.

The A creeps in because the word is said fast and the middle vowel is unstressed, so your ear supplies a generic one. Spell it from finite outward and it can’t happen.

Now go find the finite in it.