4.2a Phonology Questions

Are allophones of the same phoneme always in complementary distribution?

Allophones are, by definition, context-specific variations of a single phoneme. They are not just random sound differences—they are systematic and predictable based on the phonological environment.

When we talk about allophones, we’re referring to sounds that are similar in how they’re produced (i.e., they share features like voicing, place, or manner of articulation) and that function together in a language. Think of them like coworkers on a team: one person is great at design, the other at presenting. They’re not the same, but they contribute to the same project. Allophones do something similar: they are different phonetic realizations of the same phoneme and occur in specific environments where the other does not.

So, are allophones always in complementary distribution?

In theory, yes—complementary distribution is one of the key criteria we use to determine that two sounds are allophones of the same phoneme. However, real languages can be messy, and in some cases, certain sounds may show free variation or overlapping distribution, making the analysis more complex. But for the purposes of this course, you can assume that if two sounds are allophones, they will be in complementary distribution.

Example: [s] and [z]

In the words “sip” [sɪp] and “zip” [zɪp], the initial sounds [s] and [z] differ by only one feature: voicing. This difference changes the meaning of the word, so these two sounds are in contrastive distribution—they form a minimal pair. That means:

[s] and [z] are not allophones of the same phoneme.

They are separate phonemes in English.

They occur in the same environment (word-initial before [ɪ]), and switching them changes meaning.

What about [m] and [r] in “mow” and “row”?

These are also contrastive phonemes in English. The words “mow” [moʊ] and “row” [roʊ] form a minimal pair.

[m] and [r] can both occur before the vowel [oʊ].

Changing one for the other changes the meaning of the word.

This shows that [m] and [r] are separate phonemes, not allophones of a single phoneme.

What is the opposite of complementary distribution?

The opposite of complementary distribution is overlapping distribution. This is when two sounds can occur in the same environment, potentially changing meaning.

Example: The sounds [p] and [h] in “pat” [pʰæt] and “hat” [hæt].

Both sounds can appear at the beginning of a word before the vowel [æ].

Since they occur in the same environment and change the meaning of the word, they are contrastive phonemes in overlapping distribution.

In complementary distribution, like Clark Kent and Superman, you’ll never find both allophones in the same environment. In overlapping distribution, they can “party in the same house,” so to speak.

How do we decide which allophone is the basic form (underlying phoneme)?

In general, the basic or underlying form of a sound (the phoneme) is the allophone that:

Has the widest distribution (occurs in the most environments).

Appears in the least restricted or “default” position.

For example, if [t] occurs in more environments than [ʔ] (glottal stop) or [ɾ] (flap), we analyze /t/ as the phoneme, and the other forms as allophones of /t/.

Why does this matter? What’s the point of learning this?

This may seem abstract, but understanding phonological rules has real-world value, especially in teaching.

Example from English plurals:

[s] as in cats [kæts]

[z] as in dogs [dɔgz]

[əz] as in buses [bʌsəz]

These are all allomorphs (not allophones!) of the same plural morpheme. They are distributed based on phonological environment:

[s] appears after voiceless consonants (e.g., [t] in cats)

[z] appears after voiced consonants (e.g., [g] in dogs)

[əz] appears after sibilants (e.g., [s] or [ʃ] in buses, dishes)

This is complementary distribution, too! Each version of the plural ending occurs in a distinct environment and never overlaps.

Understanding this helps teachers:

Diagnose why students pronounce things differently or incorrectly.

Explain pronunciation patterns to learners.

Better understand how native and non-native speakers process sound systems.

Analogy: The Light Switch and Light Bulbs

Imagine a house with smart lighting. You have a single switch in the wall labeled “LIGHT” (this is the phoneme), but depending on the room, the lightbulb connected to the switch changes how it shines.

In the kitchen, the switch turns on a bright white light.

In the living room, it turns on a warm yellow light.

In the bedroom, it triggers a dim red light for relaxing.

Even though it’s the same switch, the output changes depending on the room (environment). But it’s still understood to be the same basic light source.

How this maps to phonology:

Phoneme = the switch (mental representation of a sound, e.g., /t/)

Allophones = the bulbs (physical sounds produced: [tʰ], [t], [ɾ], [ʔ])

Environment = the room (the linguistic context that determines how the phoneme is realized)

So, just like the smart lighting system changes the light depending on the room, your brain changes the pronunciation of a phoneme depending on where it appears in a word.