In linguistics, a simulfix is a type of affix that changes one or more existing phonemes in order to modify the meaning of a morpheme.

Examples of simulfixes in English are generally considered irregularities, all of which left over from pluralization rules that existed before the Great Vowel Shift. They include:

• mouse → mice
• man → men
• louse → lice
• tooth → teeth
• woman → women

See also

• Suffix (linguistics)
• Prefix (linguistics)
• Infix
• Circumfix

Affixes