Sounds of speech

Language primarily communicates through sound. These sounds can be presented in written form, and more academic work is perhaps done through reading and writing than through speech; but speech not only preceded writing in human history (and individual lives), but still forms the major part of our output. The sounds of speech are most simply divided into two kinds:

• consonants and
• vowels

Some sounds are hard to assign to to either category. In English, two are normally known as semi-vowels: the sounds represented by the letters 'y' and 'w' IPA: /w/ and IPA: /j/. For more, see semivowel. There is also an unclear group where a letter normally used as a consonant has a function like that of a vowel, in forming a new syllable: the sounds of the letters n (IPA: /n/) and l (IPA: /l/), can be syllabic consonants, as in 'trouble' (IPA: /ˈtrʌb ^əl/, and 'station' (IPA: /ˈsteɪʃ ^ən/).