The Editing Ninja: An Abusive A

Does any word misuse cause more consternation than thesimple flipping of articles a and an? The rule is simple: a comes before words beginning with aconsonant or consonant sound; ancomes before words beginning with a vowel or vowel sound.

Incorrect: Dakota ate aorange. 
Correct: Dakota ate anorange.
Incorrect: Gregory became an zombie.
Correct: Gregory became azombie.
Poor Gregory. 
Some notes:
The vowel u often makes a consonant sound (yew) at thebeginning of words such as university and unified. Therefore, a must proceed these words even thoughthey start with a vowel.
Be aware of words which begin with silent letters, such asthe h in herb or heir. Since the initial sound is a vowel, you must use an.
The sound wins every time. Yet another reason you shouldread your work aloud in the revision phase.