To illustrate how phonemes and allophones work, let’s
compare sounds to colors. If you look at the boxes below,
you’ll probably say that they’re all blue.
And yet no two of them are exactly the same color. Some are
lighter or darker, more greenish or more purplish. So why do
we call them all by the same name, “blue”? It’s because
English has a category called “blue” that includes all these
colors, not because they’re really physically identical. (In
fact, in another language the colors in these boxes might not
all have the same name. In that language, color categories
might be divided di"erently.) We could say that all these
shades of blue are “allocolors” of the same “coloreme.”
(These are not real words, so you don’t have to remember
them.) We understand them as all being “blue,” even though
they’re really slightly di"erent. They all function as the same
color.
In the same way, allophones are groups of (usually) similar
sounds that native speakers of a language recognize as being
the same sound. Speakers don’t usually even notice that the
sounds are di"erent. They just assume that they’re the same.
Types of variation among allophones
Sometimes we have a free choice of which allophone we’ll
use. For example, we usually say the phoneme /p/ this way:
Our lips come together, air pressure builds up behind our
lips, and then we release the air with a little “pop.” But when
/p/ comes at the end of a word, we might say /p/ in a
di"erent way: Our lips come together, air pressure builds up
behind our lips, and that’s all—no release. We have a free
choice of which kind of /p/ to use; at the end of a word.
Either one is all right, although one may be more common
than the other. In this example, we say the sounds are in free
variation—we can use either one.In other cases, the environment of a phoneme—the sounds
around it—determine which allophone we will use. For
example, the words car and key both start with the same
sound: /k/. But if you listen carefully and feel the position of
your tongue, you’ll notice that the /k/ sounds are not exactly
the same. When you say /k/ in car, your tongue touches
much farther back in your mouth than when you say key.
(Try whispering the two words to hear the di"erence better.
One /k/ will be higher in pitch than the other.) The /k/
sound changes because it’s a"ected by the vowel that comes
after it. The two vowel sounds are pronounced with the
tongue in a di"erent part of the mouth, and they pull the /k/19