But that doesn't mean the pronunciation of h doesn't sometimes trip up beginning Spanish students. Those who speak English as a first language often want to pronounce the letter when it is in a cognate, that is, a Spanish word that is more or less the same as English. For example, the h should not be pronounced in words such as vehículo (vehicle), Habana (Havana), Honduras and prohibir (prohibit), as tempting as it may be.
If the h is silent, why does it exist? For reasons of etymology (word history) only. Just as the "k" in the English "know" and the "b" in "lamb" used to be audible, the Spanish h used to be pronounced ages ago. Almost all Spanish consonants have become softer over the years; the h became so soft as to become inaudible.
The Spanish h also used to be used to separate two vowels that weren't pronounced as one, that is as a diphthong. For example, the word for "owl" used to be spelled as buho to indicate that it was pronounced as two syllables rather than rhyming with the first syllable of cuota or "quota." Nowadays, though, an accent is used over a stressed vowel to indicate the lack of a diphthong, so the word is written as búho. In this case, then, the accent isn't used to indicate stress as it usually does, but as a guide to proper pronunciation of the vowels.
Also, these days it is quite common for the h between vowels to be ignored in pronunciation; that is, the vowels sometimes run together despite the h between them, depending on how they are stressed. For example, prohibir is pronounced more or less the same as proibir would be. Note, though, that when the stress is on the second syllable in forms of this word, it is accented and pronounced clearly. Thus conjugated forms of the verb include prohíbes, prohíbe and prohíben.
