Glossary of Linguistic Terms

Natural Class

Definition: 

A natural class is a set of sounds that have certain phonetic features in common.

All the members of a natural class are affected in the same way in the same environment. Similarly, all members of a natural class have the same effect on other sounds that occur in their environment.

For a group of sounds to constitute a natural class,

  • they must all share one or more features and
  • there should be no other sounds in the language that have this feature or combination of features.
Examples: 

(Isthmus Zapotec, Mexico)

Voiced plosives {b, d, g} form a natural class. All the members of the set are affected the same way in the same environment.

  • For example, following the voiceless S (possessive prefix), voiced plosives are realized as the corresponding voiceless plosives. These voiceless plosives form another natural class {p, t, k}:

bere

‘chicken’

S-pere-be

‘his chicken’

biuuza?

‘guest’

S-piuuza-be

‘his guest’

daa

‘mat’

S-taa-be

‘his mat’

doo

‘rope’

S-too-be

‘his rope’

geta

‘tortilla’

S-keta-be

‘his tortilla’

gamiZa?

‘shirt’

S-kamiZa-be

‘his shirt’


(English)

Voiceless plosives form a natural class. They all have the same effect on voicing a following fricative (realized as [s]). Likewise, voiced plosives form a natural class and all have the same effect on a following fricative (realized as [z]).

map[s]

tab[z]

cup[s]

cub[z]

mat[s]

fad[z]

hit[s]

bid[z]

pack[s]

rag[z]

tick[s]

leg[z]

Glossary Hierarchy