English had a process of voicing stem-final fricatives in noun-verb and singular-plural noun word pairs. This process served to distinguish English from other Germanic languages which did not have this process. Many English word pairs exhibit the voicing alternation.
Here are examples of consonant voicing in noun-verb pairs:
The noun ends with a voiceless fricative and the verb ends with a voiceless one. The pairs choice-choose and loss-lose also have different vowel sounds.
A voicing alternation also occurs with singular-plural nouns. Here are examples:
The singular noun ends with a voiceless consonant and the plural noun ends with a voiced one. The consonant preceding the final one is also voiced. In the case of possessive nouns such as wife's and youth's, consonant voicing does not occur.
Consonant voicing was once very common in English. As a result, a number of words still exhibit a voicing alternation. This is true with two word pairs: nouns and verbs, and singular and plural nouns. This voicing alternation does not occur in other Germanic languages.