Did you hear about the guy who scammed a publisher by promising to write a dictionary of a language that doesn’t exist?

He was a lexi-con man!

The Morpheme-based Lexicon

Dr. Will Styler - LIGN 120

Previously, on LIGN 120

How are words being accessed?

How are words being built?

• “Let’s see, I need to talk about gluing this thing, again, in the past. That’s ‘glue’, plus ‘re-’, and ‘-ed’.”

• “Let’s see, I need to talk about gluing this thing, again, in the past. Looks like ‘reglued’ is the word I need!”

Today, we’ll look at one of the major approaches to the Lexicon

• We’ll think about what it means for word-building

• What it means for theory

• … and what it means about storage

• Then Monday, we’ll go the other way!

Today’s Plan

• Generative Linguistics

• The Morpheme-based Lexicon

• Problems with the Morpheme-based Lexicon

Generative Linguistics

Generative Grammar

We’ve talked a lot about generative morphology this quarter

• “Your analysis should create all of the forms in the data, without predicting anything that isn’t there”

• “Productivity should detail all the possible forms, while preventing ones which aren’t produced”

• These are generative approaches

Generative Grammar has a straightforward goal

• Describe the structure of a language in a way that outlines rules for generating “all and only” the grammatical sentences of the language

• “Let’s create rules which generate everything that’s attested in language”

• “Let’s build those rules such that they do not generate things that aren’t attested”

• The perfect generative grammar for Morphology can create every grammatical word, and forbid every ungrammatical one

For Generative Grammar, good description is good creation

• Grammar is taking known elements from an inventory and combining them by rule, then passing them on to the next level.

• Known sub-elements are combined with rules, and then passed upwards…

This is true at every level

This leads to a view of language use as assembly

• Take these pieces (phonemes, morphemes, lexemes) and put them together using rules

• Formalize the patterns as abstract rules to generate (only) the correct forms

  • Phonological rules, Morphological Rules, Syntactic Rules

• Storage is kept to a minimum!

Welcome to the Sandwich Shop

This perspective has big consequences for the storage of words!

The Morpheme-based Lexicon

We’ve been making some key assumptions about storage

• From 111: “We store phonemes, and then rules generate allophonic detail”

• “You wouldn’t want to put”cats” in the dictionary, when we could just add the -s online!”

• “We don’t need to create a whole new word, we can just combine”fuse” with “-ion”, easy!”

• Computation is cheap, storage is expensive!!

Generative Grammar comes from a time when storage was expensive and computation was cheap

As an aside, OMG

In generative approaches, storage is a last resort

• “Let’s store just raw phonemes, and generate details with rules”

• “Let’s store bare lexemes, and generate inflected forms with rules”

• “We’re not storing that in the lexicon unless we absolutely have to!”

Things that must be stored

• Phonological Irregularity

  • e.g. English ablaut, ‘exceptions’

• Morphological Idiosyncrasy

  • e.g. Fossilized forms (oxen), Class information, Mice and Deer

• Semantic Idiosyncrasy

  • e.g. Alienable vs. inalienable possession rules, animacy, and more

• We store only that which cannot be predicted by rules!

It makes for compact and graceful analysis

• … when it works well!

It also feels more economical

This has big consequences for the lexicon

Phonemes are real and are the medium of storage

• We’re not storing acoustic signals

• We’re not storing post-phonological surface forms

• We’re storing words as a series of phonemes

We’re storing as little information as we can

• Monomorphemic words

  • e.g. “cat”, “suit”, “ice”, “Germany”

• Idiosyncratic Forms

  • e.g. “oxen”, “mice”, “was”, “best”, “backpack”

• Affixes and Productive Morphological Processes

  • e.g. -s, -tion, -ify, re-, un-

Forms are stored with meanings

‘-ed’

‘cat’

‘-s’

… and rules tell us how to combine them

So, in summary…

In a morpheme-based lexicon…

• Words are stored as sequences of phonemes

• Stems and affixes are stored as unanalyzable chunks with meanings

• Storage is viewed as precious, and an effort is made to avoid doing it

• We combine these based on rules to generate the non-stored words

• Then we do phonology on the output to create legal surface forms

• All of the above is done according to abstract rules generating all and only the possible forms

Problems with a Morpheme-based Lexicon

(There are many morpheme-based theories, some of which may have different assumptions. We’re talking generally!)

This works very well if you have transparent affixation

• “cat” ‘cat’ is stored, -s ‘PL’ is stored, so combine them for ‘cat.PL’

• “walk” ‘walk’ is stored, -ed ‘PAST’ is stored, so combine them for ‘walk.PAST’

• … but we know it isn’t always like that

Efficiency Losses

Efficiency depends on regularity

… but irregularity is regular

… but irregularity is regular

As regularity is reduced, the efficiency is reduced

• Suppletive allomorphy must be stored

  • ‘Better’ cannot be derived from ‘Good’ + ‘+er’

  • ‘went’ must be stored independently of ‘go’ and ‘-ed’

• The more mice, oxen, deer, and women you have, the more you’re storing

• … but this isn’t a big issue, just more storage!

Difficulty Predicting Derived Meanings

Morpheme-based approaches thrive on predictability

• X + Y should transparently mean “X+Y”

• Bottler, Painter, Bridger, Plasterer, Lecturer, Influencer

• We can understand these words by knowing the meaning of X + the meaning of -er

• These don’t need to be stored!

  • (Note, we’re here erasing the inflection/derivation difference!)

Sometimes, we don’t have both components

• Fletcher, Cobbler, Haberdasher, Butcher, Bursar

• We don’t have the meaning of X, so they’re functionally monomorphemic

• These must be stored separately!

Sometimes, the meaning is different from the combination

• Hooker, Grinder, Hustler, Professor, Player, Mailer

• Here, there’s meaning which is not predictable based on the known components

• We must separately store the meanings of these words

… but the biggest issue is …

Non-concatenative morphology

Review: Common non-concatenative ways of adding meaning to words

• Zero Expressions

  • e.g. I sing-ø

• Conversion

  • e.g. re’peat (V) -> ’repeat (N), or ticket (N,V)

• Stem Modification

  • e.g. changing tones, vowels, consonants, orderings

• Reduplication

How are we storing zero morphemes?

• Do we have a whole bunch of meanings stored under ‘-ø’?

How do we handle multiple exponence?

• Do we write optional rules?

• Do we store morphemes with multiple forms?

How are we storing this?

What about this?

How about English ablaut?

• sit -> sat/seated, sing -> sang/sung, sting -> stung/stung, yeet -> yote/yaughten

• List of English Irregular Verbs

There are approaches to handling these phenomena!

• We could store the pattern itself as a lexical entry

• Morphemes are stored alongside stem modifications (etc.)

• Morphological processes are stored as entries, and combined with stems

• … but this quickly erases the ‘elegance’ of the approach

Morpheme-based approaches grow less compelling with increased irregularity

• Exceptions have to get stored somehow

• You end up with a bunch of edge cases

Generative linguistics is like picking up broken glass in carpet

• Disposing of the big chunks is easy and effective

• You’re gonna spend a long time chasing down those last slivers

• … and you’re still gonna need some tweezers from time to time

So, that’s a morpheme-based approach

But there is another way

Wrapping Up

• Generative approaches to grammar create all and only the attested forms

• Morpheme-based lexicons are great for efficiently handling regular patterns

• They struggle with irregularity and hard-to-memorize forms

For Next Time

• Read the Bybee paper

• We’ll talk about whole-word storage as an alternative

Thank you!