Aspirated h
In French spelling, aspirated "h" (French: ""h" aspiré") is an initial silent letter that represents a hiatus at a word boundary, between the word's first vowel and the preceding word's last vowel. At the same time, the aspirated "h" stops the normal processes of contraction and liaison from occurring. The name of the now-silent "h" refers not to aspiration but to its former pronunciation as the voiceless glottal fricative in Old French and in Middle French. Examples. This example illustrates how the aspirated "h"-word "héros" prevents the liaison, in which the otherwise-silent word-final  consonant would be pronounced before the first vowel of the following word. Because the "h" is aspirated, the second entry is incorrect, as the hiatus prevents the final from being phonetically realised. This example illustrates how the aspirated-"h" word "hibou" has no elision, in which the vowel of the "le" would be dropped. The second entry is incorrect because elision is not allowed in the word "hibou" because of the hiatus imposed by its aspirated "h". Historical and sociolinguistic aspects. One part of the major phonological changes between Latin and Early Old French was the loss of the consonant , which  would later return with the introduction of Germanic words into the language. The aspirate "h" ceased to be pronounced once more in either the 16th or the 17th century, but some grammarians kept insisting for it be pronounced into the early part of the twentieth century. Since the phonological behavior of aspirate "h" words cannot be predicted through spelling, usage requires a considerable amount of memorisation. It is often used to demonstrate one's education and social status. As early as the 17th century, noted grammarian Claude Favre de Vaugelas described the incorrect pronunciation of aspirated "h" words as  typical of French spoken on the southern side of the Loire. Further discussion of the phenomenon is found in almost every collection of remarks on language to the present day, with mistakes generally being ascribed to class differences or inattention. In modern usage, the blocking of liaison and elision with aspirated "h" words appears to be gaining ground in formal French but is losing ground in less guarded speech. List of French words which begin with an aspirated "h". The following list contains only the dictionary head entries and not all the forms that can be derived from them. For  example, it does not contain past participles or transitive verbs when used as adjectives or nouns. It does not include composite words unless the omission might cause confusion among homonyms distinguished only by diacritic signs. In French dictionaries, words with an initial aspirated "h" are traditionally prefixed with an asterisk but with no effect on their alphabetical arrangement. The following list is compiled from the "Dictionnaire du Trésor de la langue française" and the "Dictionnaire de l'Académie française". It lacks many proper names and recent borrowings. In general, if a borrowed word is pronounced with an in its language of  origin, the "h" will be conserved in French orthography and be aspirated. Words beginning with "he". Hélas. "Hélas" is not aspirated in classical poetry. That is indicated here by the use of "cet" rather than "ce". Words beginning with "hi". The aspiration of "h" is often optional in words beginning with "hi", and the liaison (with a mute "h") is generally accepted, except in recent anglicisms of current usage, interjections or homophones with another word. Beside the very productive and learned Greek root "hiéro-", most words are quite recent and of Germanic origin (German, Dutch, Modern English), or the "h  is lightly pronounced. Words beginning with ho". Most have an aspirated "h". The exceptions are mostly Latin roots that are most widely used in which the "h" has lost its voicing through assimilation to common language (in "hôte", "hospice" or "hôpital" all derived from "hospes"/"hospitis". Also if the "h" has been assimilated to the following ⟨s⟩ "heure"/"horo-", taken from "hora" in which the "h" has been assimilated to the preceding adjectives, make the "h" mute. Words beginning with "hu". Almost all words beginning with "hu" have an aspirated "h". The exceptions are some terms for which the "h" is not  etymological but was introduced for orthographic reasons with the purpose of distinguishing different roots that begin with a "u" or a "v" but were homographs in Latin writing (therefore, "huile", "huis", or "huître" are not aspirated).