This blog post (thanks Stella) explores vowels and consonants, and their phonetic reasons for being. Vowels allow the air to flow through the throat and mouth freely; consonants stop the voice to make the appropriate sound.

It follows, then, that the word vowel originates from the Latin vox meaning voice (as in vox pops, short for ‘voice of the people’, the newspaper feature where people on the street are asked their opinions). The etymology of consonant is similar; the word is a combination of the Latin com (with) and sonare (sound).

One of the comments on the post is worth repeating. Maria Eduarda wrote:

As a foreigner, I cannot cease to be amazed by English spelling. Why is loot pronounced “luut”, but door is “dor”? Why is the H not pronounced in hour? All European languages have irregularities in their spelling (I blame this Latin alphabet – why do we even have a C when there’s an S and a K? Bah!), but English is probably the most irregular language in the world. It makes written English look beautiful and interesting, but it can be tricky if you’re bad at spelling or if you’re not a native speaker and have to learn each word’s proper pronunciation.