In French, the letter H is a bit of a ghost. It is never pronounced, no matter where it appears in a word. For English speakers, this takes some getting used to. However, the H does not just stay silent. It also forces the words around it to change.
Most French words that start with an H begin with what is called a mute H. When you see a mute H, you must treat the word exactly as if it started with a vowel. Words like homme, heure, and hôtel all belong to this group. Treating them like vowels means applying two major rules of French pronunciation: elision and liaison.
Word list
heurefA1hourl'heure / les heuresheurefA1timel'heure / les heureshistoirefA1historyl'histoire / les histoireshivermA1winterl'hiver / les hivershommemA1manl'homme / les hommeshôpitalmA1hospitall'hôpital / les hôpitauxhôtelmA1hotell'hôtel / les hôtelsherbefA2grassl'herbe / les herbeshistoirefA2talel'histoire / les histoireshomme d'affairesmA2businessmanl'homme d'affaires / les hommes d'affaireshomme politiquemA2politicianl'homme politique / les hommes politiqueshôtemA2guestl'hôte / les hôteshuilefA2oill'huile / les huileshuile d'olivefA2olive oill'huile d'olive / les huiles d'olivehumainmA2humanl'humain / les humainshabitudefB1habitl'habitude / les habitudeshébergementmB1accommodationl'hébergement / les hébergementshistorienmB1historianl'historien / les historienshistoriennefB1historianl'historienne / les historienneshorairemB1timetablel'horaire / les horaireshôtemB1hostl'hôte / les hôteshôtel de villemB1city halll'hôtel de ville / les hôtels de villehôtessefB1hostl'hôtesse / les hôtesseshydrogènemB1hydrogenl'hydrogènehabiletéfB2skilll'habileté / les habiletéshabitantmB2residentl'habitant / les habitantshaleinefB2breathl'haleinehélicoptèremB2helicopterl'hélicoptère / les hélicoptèreshémisphère nordmB2Northern Hemispherel'hémisphère nordhémisphère sudmB2Southern Hemispherel'hémisphère sudhémorragiefB2bleedingl'hémorragie / les hémorragiesheure de pointefB2rush hourl'heure de pointe / les heures de pointehexagonemB2hexagonl'hexagone / les hexagoneshippopotamemB2hippopotamusl'hippopotame / les hippopotameshonnêtetéfB2honestyl'honnêtetéhorizonmB2outlookl'horizon / les horizonshorodateurmB2parking meterl'horodateur / les horodateurshoroscopemB2horoscopel'horoscope / les horoscopeshôtesse de l'airfB2flight attendantl'hôtesse de l'air / les hôtesses de l'airhumanitéfB2mankindl'humanitéhumiditéfB2humidityl'humiditéhumiditéfB2moisturel'humiditéhabitatmC1habitatl'habitat / les habitatshaltèremC1dumbbelll'haltère / les haltèreshaltérophiliefC1weightliftingl'haltérophiliehéliummC1heliuml'héliumhémisphère australmC1Southern Hemispherel'hémisphère australhémisphère boréalmC1Northern Hemispherel'hémisphère boréalhémisphère méridionalmC1Southern Hemispherel'hémisphère méridionalhémisphère septentrionalmC1Northern Hemispherel'hémisphère septentrionalherbivoremC1herbivorel'herbivore / les herbivoreshéritagemC1inheritancel'héritage / les héritageshéritagemC1legacyl'héritage / les héritageshippocampemC1sea horsel'hippocampe / les hippocampeshorizonmC1horizonl'horizon / les horizonshuîtrefC1oysterl'huître / les huîtreshumilitéfC1humilityl'humilitéhygiènefC1hygienel'hygiènehymne nationalmC1national antheml'hymne national / les hymnes nationauxhypnosefC1hypnosisl'hypnosehallucinationfC2hallucinationl'hallucination / les hallucinationshameçonmC2fishhookl'hameçon / les hameçonshémisphèremC2hemispherel'hémisphère / les hémisphèreshérésiefC2heresyl'hérésie / les hérésieshérétiqueC2hereticl'hérétique / les hérétiqueshéritiermC2heirl'héritier / les héritiershirondellefC2swallowl'hirondelle / les hirondelleshoméopathiefC2homeopathyl'homéopathiehumiliationfC2humiliationl'humiliation / les humiliationshypocrisiefC2hypocrisyl'hypocrisiehypocriteC2hypocritel'hypocrite / les hypocriteshypothèquefC2mortgagel'hypothèque / les hypothèqueshypothèsefC2hypothesisl'hypothèse / les hypothèses
Dropping vowels (Elision)
Elision is a fancy word for dropping a vowel. When a small word like le, la, or de comes right before a vowel, you drop its final letter and add an apostrophe. Because a mute H acts exactly like a vowel, the same thing happens.
This means you cannot say le homme or la histoire. Instead, they become l'homme and l'histoire. This rule applies to any word that can drop its final vowel. It makes the sentence flow more smoothly and prevents two vowel sounds from crashing into each other.
L'homme entre dans l'hôpital.
(The man enters the hospital.)
Je lis l'histoire de la France.
(I am reading the history of France.)
Il faut ajouter de l'huile d'olive.
(You must add some olive oil.)
Connecting sounds (Liaison)
The second rule is the liaison. In French, the final consonant of a word is usually silent. But if the next word starts with a vowel, that final consonant is suddenly pronounced to link the two words together. Naturally, the mute H triggers this link too.
For example, in the phrase les hommes, you will hear a clear Z sound connecting the S in les to the O in hommes. If you use the word un, like in un hôtel, you will hear an N sound linking them together. This connection is mandatory and helps maintain the musical rhythm of French.
Nous avons visité de très beaux hôtels.
(We visited some very beautiful hotels.)
Elle est arrivée il y a des heures.
(She arrived hours ago.)
Special adjectives
Treating the mute H like a vowel also affects certain adjectives. For instance, the word for "this" or "that" is ce for masculine words. But before a vowel or a mute H, it changes to cet to allow for a smooth transition, as in cet hiver.
Similarly, for feminine words, you normally use the possessive adjectives ma, ta, or sa. However, to avoid a clunky pause before a vowel sound, you must switch to the masculine forms mon, ton, and son. Therefore, even though habitude is feminine, you must say son habitude.
Il fait très froid cet hiver.
(It is very cold this winter.)
C'est son habitude de se lever tôt.
(It is his habit to wake up early.)
Summary
The golden rule for the mute H is simple: pretend the letter H does not exist at all. By imagining the word starts with the first actual vowel you see, you will naturally know when to drop vowels from words like le or la, and when to make smooth connected sounds with liaisons.