Phoneme:
* Definition: A phoneme is a basic unit of sound in a language that can distinguish one word from another. It's a mental representation of a sound.
* Key Idea: Phonemes are *contrastive*. Changing a phoneme changes the meaning of the word.
* Examples:
* In English, the sounds /p/ and /b/ are phonemes. "pat" and "bat" are different words because of the difference in the initial consonant sound.
* /k/ and /g/ are also phonemes in English, as "cat" and "gat" are different words.
Allophone:
* Definition: An allophone is a variant pronunciation of a phoneme. It's a specific realization of a phoneme in different contexts.
* Key Idea: Allophones are *non-contrastive*. Changing an allophone *doesn't* change the meaning of the word.
* Examples:
* Aspiration: The sound /p/ in "pin" is aspirated (a puff of air is released), while the /p/ in "spin" is unaspirated. Both are allophones of the phoneme /p/.
* Flapping: The /t/ in "butter" is often pronounced as a quick "flap" sound (like a "d"). This "flap" is an allophone of /t/.
* Vowel Reduction: The vowel in "about" is often reduced to a shorter, less distinct sound, especially in casual speech. This reduced sound is an allophone of the /a/ vowel.
How to Think About It:
Imagine a phoneme as a blueprint for a sound, and allophones as different ways that blueprint can be built. The blueprint is the basic idea, and the different ways it's built are just variations that don't change the essential nature of the sound.
A Helpful Analogy:
Think about the word "color" in English. We can spell it "color" or "colour," but both spellings represent the same word. These are like allophones – they are different pronunciations but represent the same phoneme.
In Summary:
* Phonemes: Distinguish words, are contrastive, and represent the mental concept of a sound.
* Allophones: Variations of a phoneme, are non-contrastive, and are influenced by phonetic context.