LT5903 Chap.3 Sound Patterns and Phonological Rules
Sound Patterns and Phonological Rules
Distribution before notation
Phonology studies how sounds are organised within a language. This chapter moves from phonotactic and sonority constraints to phoneme-allophone analysis. Contrastive distribution, complementary distribution and free variation require different evidence.
Once a predictable pattern is established, natural classes make it possible to write a compact rule specifying the underlying form, change and conditioning environment.
Assimilation, dissimilation, insertion, deletion, metathesis, strengthening and weakening provide the main process inventory.
Start with a distribution table
List every environment for each sound before deciding whether the sounds belong to one phoneme. A minimal or near-minimal pair supports contrast because replacing one sound changes meaning in the same environment.
Complementary distribution requires non-overlapping environments and a plausible phonetic relation. Free variation requires overlap without a meaning difference and may still be conditioned by style or speaker. The absence of a minimal pair alone does not prove allophony; the data may simply be incomplete.
State what the sample establishes and what a larger lexicon would need to test.
Choose an underlying representation cautiously
When two predictable variants are related, prefer an underlying form that yields the other through a simple, natural process and has a defensible elsewhere distribution. The most frequent form is not automatically underlying, and orthography is not evidence. Compare both directions.
If one requires a familiar assimilation in a clear environment while the reverse requires an unmotivated change, the first analysis is stronger. Preserve uncertainty when both derivations are equally economical or when the conditioning context is absent from the dataset.
Write a rule in four parts
A complete rule names the input, output, left and right environment, and any boundary that matters.
Feature notation should describe a natural class rather than hide a list of unrelated segments. Read the rule aloud: an input becomes an output after or before a stated context. Then test every token, including exceptions and forms where the rule should not apply. A rule that generates one desired form but wrongly changes several others has failed.
The prose explanation and notation should make identical predictions.
Distinguish similar processes by the change
Assimilation makes segments more alike, whereas dissimilation increases a difference. Insertion adds material, deletion removes it and metathesis reverses order. Strengthening and weakening depend on a change in constriction or prominence rather than on spelling.
Some surface patterns can receive more than one informal label, so specify the actual feature change. For example, calling a process assimilation is incomplete until the copied feature and trigger are identified.
Show a short derivation from underlying to surface form when ordering affects the result.
Use phonotactics as a constraint, not a verdict
Phonotactic patterns describe permitted sequences and positions within a language. Sonority can explain common syllable profiles, but language-specific restrictions still matter.
An unattested sequence may violate a structural constraint, reflect an accidental lexical gap or be repaired in borrowing. To distinguish these possibilities, compare related forms and speakers' judgements. Keep the claim language-specific: a sequence that is ill formed in one system can be ordinary in another. The analysis should connect the proposed restriction to the precise location in the syllable.
What this chapter covers
- 01
Phonotactics and sonority
- 02
Minimal pairs and phonemes
- 03
Complementary distribution and allophones
- 04
Natural classes and feature rules
- 05
Major phonological processes
Worked example · free
Diagnose a conditioned alternation
- 3State the distribution.
- 2Identify the relationship.
- 3Write the conditioning environment.
Key terms
- Phoneme
- A contrastive sound category.
- Allophone
- A non-contrastive realisation of a phoneme.
- Minimal Pair
- Two forms differing in one sound in the same environment and in meaning.
- Natural Class
- A group of sounds sharing features to the exclusion of others.
- Assimilation
- A process making one sound more like another.
Sound Patterns and Phonological Rules FAQ
What proves that two sounds are separate phonemes?
A minimal pair is strong evidence because the sounds occur in the same environment and changing one changes meaning. If the environments never overlap, examine whether context predicts their distribution before claiming a contrast.
How does free variation differ from complementary distribution?
Both can preserve meaning, but complementary distribution is predictable from the phonetic environment. Free variation lacks that conditioning. State the relevant environments explicitly rather than relying on the fact that two pronunciations sound related.
What belongs in a phonological rule?
Name the input category, the output feature or segment and the environment that conditions the change. Use natural-class features when the pattern covers a group of sounds, and treat the unchanged realisation as elsewhere unless evidence requires another rule.
Exam move
Use small data tables. Circle shared environments, mark meaning contrasts and write a prose generalisation before symbolic notation. Finish each practice by naming one form the proposed rule predicts. Test the analysis against every token and invent a new form in both a triggering and non-triggering environment.
If two underlying forms remain possible, compare the number and naturalness of operations instead of choosing by frequency or spelling.
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