Spanish and English each have five vowel letters, but the resemblance stops there.
English uses the five letters aeiou to make 12 distinct vowel sounds — those heard in beet, bit, bait, bet, bat, bot, bought, boat, book, boot, butt, and the second (unstressed) syllable of chocolate. Of course, some of these vowels merge in some dialects of English, like the vowels of cot and caught, pin and pen, or Mary, merry, and marry. [I feel quite smug about having all 12 English vowels in my own pronunciation.]
Spanish, however, has only five vowel sounds, one per vowel letter, as heard in para “for,” pera “pear,” pira “pyre,” pora “leek,” and pura “pure.” (These roughly correspond to the five vowels of bot, bait, beet, boat, and boot.) In fact, a few words in Spanish manage to use all five vowels. My favorite examples in this group are abuelito “grandfather” and murciélago “bat.” You can find some more here.
[Can any one provide other contexts (besides pVra) that fit all five Spanish vowels? Or other words that use all five (besides the ones in the link)? Edit: see Daniel’s comment!]
When Spanish and English differ, Spanish usually turns out to be normal, and English weird. (My favorite examples are noun gender, capitalization, and multiple words for “you”.) This is again the case when it comes to vowels. Here’s some cross-linguistic data on vowel inventories, borrowed from the marvelous World Atlas of Linguistic Structures Online, to back this up:
- Small vowel inventory (2-4 vowels): 93 languages
- Average vowel inventory (5-6 vowels): 288 languages
- Large vowel inventory (7-14 vowels): 183 languages [German wins!]
With 12 vowels, English is indeed an outlier.
In fact, if we were to take a closer look at which 5 vowels Spanish uses, it would become even clearer exactly how normal Spanish is. But that’s a matter for another post.