Phoneme, Allophone, Morpheme, Allomorph

Phoneme is one of a small set of speech sounds that are distinguished by the speakers of a particular language and it make a difference to meaning.. The term is usually restricted to vowels and consonants.  
For example in English : /m/ of mat and the /b/ of  bat.

An Allophone is one of several similar speech sounds (phones) that belong to the same phoneme.
For example in English :
 [ph] as in pin and [p] as in spin are allophones for the phoneme /p/ in the English language because they cannot distinguish words. They are different, the first is aspirated and the second is unaspirated (plain).

The relationship between a phoneme and allophones :
1. A phoneme is manifested as one or more phones (phonetic sounds) in different environments. These phones are called allophones.
2. A phoneme is a set of allophones or individual non-contrastive speech segments. Allophones are sounds, whilst a phoneme is a set of such sounds.

The differentiate between a phoneme and allophones :
The phoneme placed in slant brackets (/ /) and the allophones placed in square brackets ([ ]).

Morpheme is a meaningful linguistic unit consisting of a word (such as dog) or a word element (such as the -s at the end of dogs) that cannot be divided into smaller meaningful parts.
A morpheme cannot be split into smaller meaningful units, but a word can.
A word can be analyzed as consisting of one morpheme or two or more morphemes.
For example in English :
1. The word sad as consisting of one morphemes.
2. The word uninterested as consisting of three morphemes: un-, interest, and -ed.

An allomorph is one of two or more complementary morphs which manifest a morpheme in its different phonological or morphological environments.
For example in English :
The prefixes in- (insane), il- (illegible), im- (impossible), ir- (irregular) are allomorphs of the same negative morpheme.

The relationship between a morpheme and allomorphs :
When a morpheme is represented by a segment, that segment is a morph. If a morpheme can be represented by more than one morph, the morphs are allomorphs.  A morpheme is manifested as one or more morphs (surface forms) in different environments. These morphs are called allomorphs.

Retya Elsivia

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