Phonology

Phonology is the branch of linguistics that studies the patterning of speech sounds in languages. To a large extent, it is related to phonetics but has a different focus. Whereas phonetics concentrates on the physical articulatory and auditory aspects of speech sounds, phonology investigates sound types that subsume all the variations of speech sounds which we actually produce while speaking. It also concentrates on native speaker’s linguistic knowledge about the sound arrangements in their language. This knowledge is mostly intuitive. 

The central term in phonology is phoneme, which is defined as the smallest meaning distinguishing sound unit. In other words, phonemes can distinguish words with different meanings. For example, /p/ and /b/ are two separate phonemes because they can distinguish words (pit and bit; pull and bull, etc.). 

Minimal Pairs
Minimal pairs are words with different meanings that have the same sounds except for one.  

Free Variation
Some words in English are pronounced differently by different speakers 

Phones and Allophones
Phonemes are not physical sounds. They are abstract mental representations of the phonological units of a language. Phones are considered to be any single speech sound of which phonemes are made. The different phones that are the realization of a phoneme are called allophones of that phoneme. 

Complementary Distribution
If two sounds are allophones of the same phoneme, they are said to be in complementary distribution. These sounds cannot occur in minimal pairs and they cannot change the meaning of otherwise identical words. 

A distinction is made between phonetic and phonological transcription. Phonetic transcription is given in square brackets, [ ], and phonological transcription employs slashes, / /. A distinction is made between phonetic and phonological transcription. Phonetic transcription is given in square brackets, [ ], and phonological transcription employs slashes, / /.