H

In English, ⟨h⟩ occurs as a single-letter grapheme (being either silent or representing the voiceless glottal fricative (/h/) and in various digraphs, such as ⟨ch⟩ /tʃ/, /ʃ/, /k/, or /x/), ⟨gh⟩ (silent, /ɡ/, /k/, /p/, or /f/), ⟨ph⟩ (/f/), ⟨rh⟩ (/r/), ⟨sh⟩ (/ʃ/), ⟨th⟩ (/θ/ or /ð/), ⟨wh⟩ (/hw/[9]). The letter is silent in a syllable rime, as in ah, ohm, dahlia, cheetah, pooh-poohed, as well as in certain other words (mostly of French origin) such as hour, honest, herb (in American but not British English) and vehicle (in certain varieties of English). Initial /h/ is often not pronounced in the weak form of some function words including had, has, have, he, her, him, his, and in some varieties of English (including most regional dialects of England and Wales) it is often omitted in all words (see '⟨h⟩'-dropping). It was formerly common for an rather than a to be used as the indefinite article before a word beginning with /h/ in an unstressed syllable, as in "an historian", but use of a is now more usual (see English articles § Indefinite article). In English, The pronunciation of ⟨h⟩ as /h/ can be analyzed as a voiceless vowel. That is, when the phoneme /h/ precedes a vowel, /h/ may be realized as a voiceless version of the subsequent vowel. For example the word ⟨hit⟩, /hɪt/ is realized as [ɪ̥ɪt].[10] H is the eighth most frequently used letter in the English language (after S, N, I, O, A, T, and E), with a frequency of about 4.2% in words. When h is placed after certain other consonants, it modifies their pronunciation in various ways, e.g. for ch, gh, ph, sh, and th.

In the German language, the name of the letter is pronounced /haː/. Following a vowel, it often silently indicates that the vowel is long: In the word erhöhen ('heighten'), the second ⟨h⟩ is mute for most speakers outside of Switzerland. In 1901, a spelling reform eliminated the silent ⟨h⟩ in nearly all instances of ⟨th⟩ in native German words such as thun ('to do') or Thür ('door'). It has been left unchanged in words derived from Greek, such as Theater ('theater') and Thron ('throne'), which continue to be spelled with ⟨th⟩ even after the last German spelling reform.

In Spanish and Portuguese, ⟨h⟩ ("hache" in Spanish, pronounced ['atʃe], or agá in Portuguese, pronounced [aˈɣa] or [ɐˈɡa]) is a silent letter with no pronunciation, as in hijo [ˈixo] ('son') and húngaro [ˈũɡaɾu] ('Hungarian'). The spelling reflects an earlier pronunciation of the sound /h/. In words where the ⟨h⟩ is derived from a Latin /f/, it is still sometimes pronounced with the value [h] in some regions of Andalusia, Extremadura, Canarias, Cantabria, and the Americas. Some words beginning with [je] or [we], such as hielo, 'ice' and huevo, 'egg', were given an initial ⟨h⟩ to avoid confusion between their initial semivowels and the consonants ⟨j⟩ and ⟨v⟩. This is because ⟨j⟩ and ⟨v⟩ used to be considered variants of ⟨i⟩ and ⟨u⟩ respectively. ⟨h⟩ also appears in the digraph ⟨ch⟩, which represents /tʃ/ in Spanish and northern Portugal, and /ʃ/ in varieties that have merged both sounds (the latter originally represented by ⟨x⟩ instead), such as most of the Portuguese language and some Spanish dialects, prominently Chilean Spanish.

In French, the name of the letter is written as "ache" and pronounced /aʃ/. The French orthography classifies words that begin with this letter in two ways, one of which can affect the pronunciation, 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 for example the singular definite article le or la, which is elided to l' before a vowel, elides before an H muet followed by a vowel. For example, le + hébergement becomes l'hébergement ('the accommodation'). The other kind of ⟨h⟩ is called h aspiré ("aspirated '⟨h⟩'", though it is not normally aspirated phonetically), and does not allow elision or liaison. For example in le homard ('the lobster') the article le remains unelided, and may be separated from the noun with a bit of a glottal stop. Most words that begin with an H muet come from Latin (honneur, homme) or from Greek through Latin (hécatombe), whereas most words beginning with an H aspiré come from Germanic (harpe, hareng) or non-Indo-European languages (harem, hamac, haricot); in some cases, an orthographic ⟨h⟩ was added to disambiguate the [v] and semivowel [ɥ] pronunciations before the introduction of the distinction between the letters ⟨v⟩ and ⟨u⟩: huit (from uit, ultimately from Latin octo), huître (from uistre, ultimately from Greek through Latin ostrea).

In Italian, ⟨h⟩ has no phonological value. Its most important uses are in the digraphs 'ch' /k/ and 'gh' /ɡ/, as well as to differentiate the spellings of certain short words that are homophones, for example some present tense forms of the verb avere ('to have') (such as hanno, 'they have', vs. anno, 'year'), and in short interjections (oh, ehi).

Some languages, including Czech, Slovak, Hungarian, Finnish, and Estonian use ⟨h⟩ as a breathy voiced glottal fricative [ɦ], often as an allophone of otherwise voiceless /h/ in a voiced environment.

In Hungarian, the letter has no fewer than five pronunciations, with three additional uses as a productive and non-productive element of digraphs. The letter h may represent /h/ as in the name of the Székely town Hargita; intervocalically it represents /ɦ/ as in tehén; it represents /x/ in the word doh; it represents /ç/ in ihlet; and it is silent in cseh. As part of a digraph, it represents, in archaic spelling, /t͡ʃ/ with the letter c as in the name Széchenyi; it represents, again, with the letter c, /x/ in pech (which is pronounced [pɛxː]); in certain environments it breaks palatalization of a consonant, as in the name Beöthy which is pronounced [bøːti] (without the intervening h, the name Beöty could be pronounced [bøːc]); and finally, it acts as a silent component of a digraph, as in the name Vargha, pronounced [vɒrgɒ].

In Ukrainian and Belarusian, when written in the Latin alphabet, ⟨h⟩ is also commonly used for /ɦ/, which is otherwise written with the Cyrillic letter ⟨г⟩.

In Irish, ⟨h⟩ is not considered an independent letter, except for a very few non-native words, however ⟨h⟩ placed after a consonant is known as a "séimhiú" and indicates lenition of that consonant; ⟨h⟩ began to replace the original form of a séimhiú, a dot placed above the consonant, after the introduction of typewriters.

In most dialects of Polish, both ⟨h⟩ and the digraph ⟨ch⟩ always represent /x/.

In Basque, during the 20th century it was not used in the orthography of the Basque dialects in Spain but it marked an aspiration in the North-Eastern dialects. During the standardization of Basque in the 1970s, the compromise was reached that h would be accepted if it were the first consonant in a syllable. Hence, herri ("people") and etorri ("to come") were accepted instead of erri (Biscayan) and ethorri (Souletin). Speakers could pronounce the h or not. For the dialects lacking the aspiration, this meant a complication added to the standardized spelling.

As a phonetic symbol in the International Phonetic Alphabet (IPA), it is used mainly for the so-called aspirations (fricative or trills), and variations of the plain letter are used to represent two sounds: the lowercase form ⟨h⟩ represents the voiceless glottal fricative, and the small capital form ⟨ʜ⟩ represents the voiceless epiglottal fricative (or trill). With a bar, minuscule ⟨ħ⟩ is used for a voiceless pharyngeal fricative. Specific to the IPA, a hooked ⟨ɦ⟩ is used for a voiced glottal fricative, and a superscript ⟨ʰ⟩ is used to represent aspiration.

• H with diacritics: Ĥ ĥ Ȟ ȟ Ħ ħ Ḩ ḩ Ⱨ ⱨ ẖ ẖ Ḥ ḥ Ḣ ḣ Ḧ ḧ Ḫ ḫ ꞕ Ꜧ ꜧ
• IPA-specific symbols related to H: ʜ ɦ ʰ ʱ ɥ ᶣ[11] ɧ
• Superscript IPA symbols related to H:[12] 𐞖 𐞕
• ꟸ: Modifier letter capital H with stroke is used in VoQS to represent faucalized voice.
• ᴴ : Modifier letter H is used in the Uralic Phonetic Alphabet[13]
• ₕ : Subscript small h was used in the Uralic Phonetic Alphabet prior to its formal standardization in 1902[14]
• ʰ : Modifier letter small h is used in Indo-European studies[15]
• ʮ and ʯ : Turned H with fishhook and turned H with fishhook and tail are used in Sino-Tibetanist linguistics[16]
• Ƕ ƕ : Latin letter hwair, derived from a ligature of the digraph hv, and used to transliterate the Gothic letter 𐍈 (which represented the sound [hʷ])
• Ⱶ ⱶ : Claudian letters[17]
• Ꟶ ꟶ : Reversed half h used in Roman inscriptions from the Roman provinces of Gaul[18]

• 𐤇 : Semitic letter Heth, from which the following symbols derive
  • Η η : Greek letter Eta, from which the following symbols derive
    • 𐌇 : Old Italic H, the ancestor of modern Latin H
      • ᚺ, ᚻ : Runic letter haglaz, which is probably a descendant of Old Italic H
    • Һ һ : Cyrillic letter Shha, which derives from Latin H
    • И и : Cyrillic letter И, which derives from the Greek letter Eta
    • 𐌷 : Gothic letter haal

• h : Planck constant
• ℏ : reduced Planck constant
• ${\displaystyle \mathbb {H} }$ : Blackboard bold capital H used in quaternion notation