H is the eighth letter of the Latin alphabet.
The Semitic letter ח (khêt) probably represented the (pharyngeal voiceless fricative) (IPA ). The form of the letter probably stood for a fence. The early Greek H stood for /h/, but later on this letter eta (Η, η) stood for /ɛ:/. In Modern Greek this phoneme fell together with /i/, similar to the English development where EA /ɛ:/ and EE /e:/ came to be both pronounced/i:/.
In Etruscan and Latin, the sound value /h/ was maintained, but all Romance languages lost the sound — subsequently Romanian borrowed the /h/ phoneme from its neighbouring Slavic languages, Spanish developed a secondary /h/ from F and then lost it again, and Castilian /x/ has developed an [h] allophone in some Spanish-speaking countries. In German, h is typically used as a vowel lengthener as well as the letter for the phoneme /h/. This may be because /h/ was sometimes lost between vowels in German, but it may also have to do with the fact that Romance lost /h/. Hence, H is used in many spelling systems in digraphs and trigraphs such as ch in Spanish and English /tʃ/, French /ʃ/ from /tʃ/, Italian /k/, German /x/.
Usage in English
In reference, it is spelled aitch (or sometimes haitch by speakers of dialects—primarily Irish and Australian English—which pronounce an h in the name of the letter itself). The English name aitch /eɪtʃ/ or haitch /heɪtʃ/ derives from Old French /atʃ/ > Middle English /a:tʃ/; /heɪtʃ/ is thus a spelling pronunciation based on the sound usually associated with the English letter.
Usage in French
The French language classifies words that begin with this letter in two ways that must be learned to use French properly, even though it is a silent letter either way. The h muet, or "mute h", is considered as though the letter were not there at all, so masculine nouns get the article le replaced by the sequence l'. Similarly, words such as un, whose pronunciation would elide onto the following word would do so for a word with h muet.
The other way is called h aspiré, or "aspirated h" (though it is still not aspirated) and is treated as a phantom consonant. Hence masculine nouns get the le, separated from the noun with a bit of a glottal stop. There is no elision with such a word; the preceding word is kept separate by similar means.
Dictionaries mark those words that have this second kind of h with a preceding mark, either an asterisk, a dagger, or a little circle lower than a degree-symbol.
Hotel represents the letter H in the NATO phonetic alphabet. To ensure compatibility with those languages that do not pronounce this letter, this word is officially pronounced with the letter H silent.
In international Morse code the letter H is DitDitDitDit: · · · ·
In Braille the letter H is represented as ⠓ (in Unicode), the dot pattern,
In Unicode the capital H is codepoint U+0048 and the lowercase h is U+0068.
The ASCII code for capital H is 72 and for lowercase h is 104; or in binary 01001000 and 01101000, correspondingly.
The EBCDIC code for capital H is 200 and for lowercase h is 136.
The numeric character references in HTML and XML are "H" and "h" for upper and lower case respectively.
Meanings for H
- In biochemistry, H is the symbol for histidine.
- In chemistry, H is the symbol for hydrogen.
- In computing, ^H is often used jokingly to indicate the intended deletion of the previous letter. This is because some operating systems display ^H when pressing the backspace key if the keyboard is not configured properly.
- In Japanese, H was originally an abbreviation for "hentai" (pervert). It has come to mean sexual, as in H games (pornographic computer games) or H suru (meaning "to have sex"). Through the popularity of anime (Japanese animation), the old incorrect meaning has become known to fans in the west. See also Ecchi.
- In international licence plate codes, H stands for Hungary.
- In mathematics, blackboard bold represents the quaternions (after William Rowan Hamilton, representing the rationals).
- In the Metric system,
- In music, H is a note in the German system, corresponding to B natural.
- In physics, h is Planck's constant.
- In thermodynamics, h is enthalpy.
H is the stage name of Ian Watkins, formerly of the pop group Steps.
- As the first letter of a postal code,
- In science fiction fandom and hacker jargon, the infix of an h is a method of "marking" common words, i.e., calling attention to the fact that they are being used in a nonstandard, ironic, or humorous way. It is likely to have originated in the fannish catch phrase “Bheer is the One True Ghod!” from the mid-20th Century. The h infix marking of "Ghod" and other words spread into the 1960s counterculture via underground comics, and into early hackerdom either from the counterculture or from SF fandom (the three communities overlapped heavily at the time). More recently, the h infix has become an expected feature of benchmark names (Dhrystone, Rhealstone, etc.); this is probably patterning on the original Whetstone (the name of a laboratory) but influenced by the fannish/counterculture h infix.