Fricative Voicing in English Plurals

A number of English plurals exhibit fricative voicing in the stem. The fricatives are the alveolar fricative, the interdental fricative and the labiodental fricative. In the case of the interdental fricative, voicing is common in British English but not in American English.

The plurals baths and paths have a voiced interdental fricative in British English. In American English, however, the interdental fricative is voiceless. Since fricatives agree in voicing, British English has two voiced fricatives in these words, and American English has two voiceless ones.

Voicing also occurs in the plurals blouses and houses. The alveolar fricative of blouse and house becomes voiced in the plural forms.

In the following words, the labiodental fricative is voiced:

calves
halves
knives
leaves
lives
loaves
shelves
thieves
wives
wolves

In Old English the e of the plural was pronounced. The word wife was originally pronounced with two syllables. The /f/ voiced because it was between two voiced segments. This is an example of  voicing assimilation.

Certain plurals have optional voicing. Examples include elfs/elves, hoofs/hooves, roofs/rooves, scarfs, scarves, and wharfs/wharves. However, in certain plurals, no voicing can occur. Plurals which belong to this category include chiefs, cliffs and safes.

In Danish, Norwegian and Swedish voicing of the labiodental fricative is more extensive than it is in English. This is because in the North Germanic languages it applies not only to the plural but also to the singular form. For example, knife/knives is kniv/knivar in Swedish, kniv/kniver in Norwegian and kniv/knive in Danish.

Many English plurals have stem-final fricative voicing. This is the result of voicing assimilation which occurred in Old English. The voicing rule is not categorical because a number of English plurals do not exhibit fricative voicing.