If you’ve taken some basic French classes, you’ll probably recall being taught that the h is not pronounced in French. So heure (“time, hour”) and Eure (the name of a French river and department) are pronounced identically. You were then probably taught that a word beginning with h behaves as though it began with a vowel so that, for example, “the time” is l’heure, not *la heure, just as “the water” is l’eau and not *la eau. And in trois heures (“three hours, three o’clock”), the s is pronounced before the following vowel, just as it would be in trois arbres (“three trees”).
But it turns out that this isn’t the whole story. It is true that in standard French, the h is always “silent”. But in some words, the h still represents a special “feature”: it counts as a consonant when deciding whether to pronounce the s (or other consonant) that comes before it, and also when deciding whether to use le/la or l’ (or du/de la/d’).
So, how does this work? Well, the masculine words héros (“hero”) and hérisson (“hedgehog”) are examples of these special words. Looking at them, you might have expected the French for “the hero” and “the hedgehog” to be *l’héros and *l’hérisson. But in these cases, the words behave as if they actually began with a consonant-even though the h is “silent”-and so French speakers say le héros and le hérisson. If you’ve heard of the film La Haine, you might have wondered why it isn’t L’haine. Well, haine (“hatred”) is one of these special words!
Linguists call this phenomenon “aspirate h” or “h aspiré” (this misleading term is derived from the fact that, in the language’s history, the h was actually pronounced or “aspirated” in some of these words). Other common examples with an “aspirate h” include: la hache (“axe”), la haie (“hedge”), le hameau (“hamlet”), le hareng (“herring”), le hasard (“chance, luck, fate”), le homard (“lobster”), la honte (“shame”) along with huit (“eight”), haut (“high, tall”). So in the expression en haut (“at the top, upstairs”), you don’t pronounce the n because haut has an “aspirate h“. (In dix-huit, as you are probably aware, the x is pronounced: “di-z-(h)uit”.)
There are a few other complications with these words. One particular difficulty is that there is some variation from speaker to speaker as to which words are given an “h aspiré”. So some speakers will say le haricot (“the bean”) while others l’haricot; some will say le Hollandais (“the Dutchman”) while others l’Hollandais.
It also turns out that a so-called “aspirate h” word doesn’t even have to be spelt with a letter h! The words onze and yaourt (“yoghurt”), and often foreign words beginning with a vowel, all behave as though they began with an “aspirate h“, and so you say e.g. le onze septembre, le yaourt, and the s is not pronounced in le(s) onze personnes, le(s) yaourts (whereas notice that it is in les yeux). These special cases are generally words beginning with a “glide” or semivowel. They can be spelt with a ‘w’, ‘y’ or combination of what are traditionally classed as “vowel” letters. Other examples include le iambe, la ouate, le yoga, le western, le wiki…
We have given a brief overview here of what is actually quite a complex area of French pronunciation. If you are a relative beginner, it is worthwhile being aware of this phenomenon without getting bogged down. Advanced students will have fun getting to grips with the complexities…