Allophones are PREDICTABLE from the phonetic environment where they occur.
Phonemes are NOT predictable from the phonetic environment where they occur.
Plural phoneme /s/
[s], [z], [Vz]
Cat ==> /s/
because we can predict that a voiceless consonant like /t/ can only take the plural allophone /s/
Bags ==> /z/
Because the last sound in "bag" is voiced. Therefore, we can predict that the plural allophone here is /z/
The phonetic environment is indicative of what type of allophone is to be used.
Are phonemes predictable from the phonetic environment?
NO, phonemes are not predictable from the phonetic environment where they occur.
P....
We cannot predict phonemes from the phonetic environment where they occur, but we can predict allophones.
Zawawi