In English, the number of sounds is around 50 – almost equally divided between
consonants and vowels – varying somewhat between dialects and between different
ways of analyzing the English phonological system. There is no connection between
the meaning and any of the sounds. If the /I/ of /sIt/ is replaced by /U/, we get /sUt/,
spelt soot, which has the meaning ‘a black powdery form of carbon produced when
coal, wood, or oil is burned, which rises up in fine particles with the flames and
smoke’. This meaning is totally unrelated to the meaning ‘to assume a position of rest
in which the weight is largely supported by the buttocks’, despite the fact that the
units /sIt/ and /sUt/ both start with /s/ and end with /t/ and have a vowel in between,
and the difference in meaning is in no way connected to the phonetic difference
between the vowels /I/ and /U/. If /t/ in /sIt/ is replaced by /k/, we get the sound
sequence /sIk/, spelt sick, which is used to express another completely unrelated
meaning: ‘affected by an illness’.