In reply to:
I usually say "an" if the h is silent. An herb. But if I pronounce the h then I use "a." A hospital. I think I picked up the habbit from Spanish class. For example, a feminine word that starts with "a" gets the masculine article because it is easier to say. You would say el agua, as apposed to la agua even though agua should be a feminine word. Another example would be el algebra.
Intriguing. I find it interesting that you pick herb as an example of a word with a "silent" h. I'm with shanks on this one, a herb, a horse, an historical, an hotel. The "el algebra" brought a smile to my face for the way that etymology can create redundant pairings - one source list algebra as derived from the Arabic al-jebr - the union of broken parts, or according to another source, the resetting of anything broken - so in this case el al is "the the" rather than an airline. Which doesn't change the fact that algebra always left my synapses feeling like broken parts in need of resetting.
