So let’s talk about shapeshifting. We can
usually count on the things that we see to stay
pretty much the way that they are. And it seems
like words should work that way, too. When
we pick them out inside of our heads, we figure they’re
going to spring out into the world 
the same way, each and every time. But our precious
little meaning bits get up to some shifty
tricks during the dark hours. You have to
listen carefully to hear what they really
do. I’m Moti Lieberman, and this is 
the Ling Space.
So we’ve talked a couple of times before
about morphemes, the smallest pairings between
sound and meaning. Our mental dictionary isn’t
really made up out of words; words are just
too big. Instead, it’s made out of morphemes.
We’ve got things like nouns and verbs, and
also little bits like negation and tense or
change-y things like that [i] that morphs
a noun into an adjective. Those are all morphemes.
So our brain holds a lot of these entries,
and when you learn a new one, you need to
encode some vital information into your neurons.
You need to know what a morpheme means,
and whether it can stand on its own or if
it has to be attached to something else, etc.
But another essential thing that we need
to learn is how to pronounce it. So let’s
say that you know that English has a free-standing
noun that means a 60 minute time period.
If you think the right way to say that word is
“huor,” it’s not likely that your Anglophone
peers are going to agree that you
know the word “hour.” Maybe it’s not
surprising that the way that you say the word is really important. And a lot of the morphemes in
any language you could care to think of, be
it Swiss German, Salish, or Swahili, get
pronounced pretty much the same way every time that you say
them. Sure, you might say things a little
bit differently every time you shoot the words
out of your mouth.
You won’t evoke any eyebrow raising if you say "evoke" slightly differently
one time to the next; there’s some natural
wiggle room. Chances are really good that
you’re not actually a robot. But some morphemes go
further than this. Some of them really do
get pronounced noticeably differently depending
on the context where they show up, so what
other morphemes they attach to, and what sounds
they’re near.
These morphemes are like chameleons: they see who else is around, and then they change up their
look and sound to try to fit in.We call these environmentally conditioned
morpheme pronunciation switch-ups allomorphy.
Each version of the morpheme that gets produced
is known as an allomorph.
Now, that term might sound kind of familiar
to you. Maybe it reminds you of another allo-concept
that we talked about back in Topic 5 with
regard to phonology, the allophone. And they
really do have a lot in common. Allophones
are different versions of a phoneme that pop
out of our mouths depending on what they get
pronounced near. If you swap out phoneme for
morpheme in that definition, you’d get a
pretty good understanding of what allomorphy is.
So what’s the difference between these two?
Well, broadly speaking, the rules that turn
phonemes into allophones will always apply to
that sound if it’s in the right environment.
You stick a /t/ at the beginning of a stressed
syllable, and it’s getting aspirated. It
could be in tower, attack, or tarot, but you’re
always gonna get that puff of air.
The rules that make allomorphs cause pronunciation
changes, too, but they’re specifically tied
to the morpheme that they apply to. Let’s look
at an example. You probably think that you
know the English plural, right? It’s that
–s that you put at the end of a noun, usually.
But that’s not really true, when you think
about pronunciation. Sure, you do get that
[s] sound when you put it after a voiceless
consonant, like in [bowts] or [poɹts].
But you actually get a [z] if it follows a
voiced sound, like in [dɑgz] or [kɑɹdz].
And beyond that, if you’ve got a noisy hissy
sibilant sound at the end of your noun, you
actually get a whole extra [ɪz], like
going from one [pʌntʃ] to several [pʌntʃɪz],
or from one [dæns] to some [dænsɪz].
But the changes are tied specifically to
the morpheme. You may have to put [z] on
the end of [æb] to make [æbz],
but in the middle of a word, you can throw
that [æb] right in front of [s] sound and be totally fine, like in [æbsənt]. You
don’t end up with either [æpsənt] or [æbzənt].
The rule’s just there for the plural - it
has to do with the morpheme, and not just the sounds in it.
Some of the time, we’ll encode this allomorphy
into the way that we spell things. Take a look at
the prefix [ɪn-] in English. This attaches
to adjectives, and turns them into their opposite.
So like if you have [dajɹɛkt], throwing
that [ɪn] on the front makes it less straightforward.
Now, [n] and [d] share the same place of articulation;
they're both made by cutting off the air
flow at the alveolar ridge.
But look at what happens when you pronounce
that [ɪn] in front of a
labial sound, like [p]. Suddenly that
[ɪn] becomes downright [ɪmpɹɑpɚ]. The
nasal sound moves forward to get pronounced
with the [p], and we reflect that in the spelling.
But don’t get your hopes up too much
about spelling again, because it still doesn’t
show up for the [ɪŋ] that you get in [ɪŋkɹɛdɪbl̹].
Or if you’re like me, you make a cool labiodental
nasal when you put the [ɪɱ] in front of [ɪɱvɑləntɛɹi].
And you don’t even do it on purpose! The
spelling doesn’t capture these… maybe
because English doesn’t have as many symbols
as the IPA, or maybe just because it doesn’t
care. We can find the exact same variation
for another negative prefix, [ʌn], and none
of those get reflected in the spelling, either:
unbelievable, unfair, untimely, uncomfortable,
and those all get spelled with un-.
Just remember: even if it helps sometimes,
you should never bet on spelling to be helpful. English spelling usually hates you.
Before you think that we’re just looking
at changes where you put one sound up
to the next and they influence each other,
we should tell you that allomorphy can get
pretty extreme. Back on our website, we’ll
talk about some other examples, but the switchover
from one way of realizing a morpheme to another
can take, well, ALL THE SOUNDS. This
is a process known as suppletion.
Let’s take a look at an example from Japanese.
Now, negation for verbs in Japanese is usually
pretty straightforward. You take the verb
root, you strip the [ɯ] off the end, and you stick
on [anai]. So [manabɯ], to learn, becomes
[manabanai]; [mawaɾɯ], to spin, becomes
[mawaɾanai], etc. So for the verb to be,
[aɾɯ], you probably would expect something
along those lines for negation. Like, [aɾanai].
I mean, we just saw mawaɾanai, right? But
no, when you negate it, you just get [nai].
All of [aɾɯ] has ceased to be. That’s
suppletion. But even these extreme examples
are driven by rules. You store one base morpheme
in your mind, and then you change it over
to the appropriate allomorph depending on
what it finds itself attached to. So that
raises the question, how do we know which
allomorph is the underlying form?
How do we know what version of the morpheme
is stored in your mind, and what’s generated
by rules? And here again we can find a strong
similarity to allophones: the one that's
going to be the underlying form is the one that appears in the largest number of environments. To see
this, let’s go back and look at [ɪn] again,
so we can solve the mystery of what its underlying
form is, [ɪm], [ɪɱ], [ɪn], or [ɪŋ].
Just on the basis of that, it might seem hard. After all, each has its defined environment. But
only [ɪn] shows up when the following sound
doesn’t have a place of articulation for
the nasal to match – that is, when the following
morpheme starts with a vowel. Using any other
nasal than [n] would be inappropriate in "inappropriate".
That means the [n] version has the broadest
distribution - it shows up before alveolar
sounds, and also vowels. That determines that
it’s the underlying form of the morpheme.
And sometimes, the default allomorph is actually
the least likely regular version of the morpheme
around. For that, let’s take a look at the
German plural. This has five different allomorphs:
-en, -e, -er, -s, and... nothing.
Some words don’t change when they become
plurals, but this lack of overt sound change
still needs to be recorded in the German
mental dictionary. So that’d be like Auge
turning to Augen; Jahr becoming Jahre; Geist
becoming Geister; Auto becoming Autos;
and Onkel just staying Onkel. So German has
a couple more regular plural allomorphs than
English does.
But the rules that govern them are rather
more complicated; it’d be difficult to give you
a complete description without making a whole episode
just about that, so instead, we’ve
put a link down in the description for those of you who are curious. And depending on how you do your numbers,
you'll get different frequency counts for
the different allomorphs. But there’s no arguing:
of the five, -en is by far the most common,
with 42% to 68% of plurals going that route.
And -s is the least common, getting only 1
to 8% of the plural love. And yet… we want
to say that -s is actually the default version
of the plural. And it’s for the same reasons
as before - it shows up in the most different environments. If we look at what plural allomorph gets applied
to newly coined expressions, or to borrowed
words, like "Kinos" for movies or "Chefs" for
bosses, it’s the humble, infrequent -s that
gets called out.
When we define a morpheme, and we say it’s
the smallest pairing between sound and meaning?
It turns out it doesn’t always have to be the
exact same sound. There’s some patterns
of variation there, and our little nuggets of meaning
can put on a bunch of different costumes to get
the job done. But even if they shift around,
if you know the rules, you can work it out.
So we’ve reached the end of the Ling Space
for this week. If you didn’t lose all of
your sounds in suppletion, you learned that
morphemes vary in their pronunciation in a
rule-based manner; that the resulting allomorphs
range from changing one portion of one sound
to all of the sounds in the whole word; and that
we can find the default morpheme by seeing
which form shows up in the most environments.
The Ling Space is produced by me, Moti Lieberman.
It’s directed by Adèle-Elise Prévost,
and it’s written by both of us. Our production
assistants are Georges Coulombe and Stephan
Hurtubise, our music and sound design is by
Shane Turner, and our graphics team is atelierMUSE.
We’re down in the comments below, or you
can bring the discussion back over to our
website, where we have some extra material
on this topic. Check us out on Tumblr, Twitter
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your own personal Ling Space, please subscribe.
And we’ll see you next Wednesday. Baamaapii
miinwaa kaawaabmin!
