H.
His a note of aspiration, and shows that the following vowel must be pronounced with a strong emission of breath, as hat, horse.
It seldom begins any but the first syllable, in which it is always sounded with a full breath, except in heir, herb, hostler, honour, humble, honest, humour and their derivatives.
It sometimes begins middle or final syllables in words compounded, as blockhead; or derived from the Latin, as comprehend.