Regular plurals

The plural morpheme in English is suffixed to the end of most nouns. Regular English plurals fall into three classes, depending upon the sound that ends the singular form:

Where a singular noun ends in a sibilant sound —/s/, /z/, /ʃ/, /ʒ/, /tʃ/ or /dʒ/— the plural is formed by adding /ɨz/. The spelling adds -s, or -es if the singular already ends in -s: