An exponent is a phonological manifestation of a morphosyntactic property. In non-technical language, it is the expression of one or more grammatical properties by sound. There are several kinds of exponents:

• identity
• affixation
• reduplication
• internal modification

(please note these examples will use regular orthography rather than phonetic transcription due to the lack of IPA support in HTML)

Identity

The identity exponent is both simple and common: it has no phonological manifestation at all.

English Example:
DEER + PLURAL → deer

Affixation

Affixation is the addition of a prefix, suffix, or infix to a word.

English Example:
WANT + PAST → wanted

Reduplication

Reduplication is the repetition of part of a word.

Sanskrit Example:
DA ('give') + PRESENT + ACTIVE + INDICATIVE + FIRST PERSON + SINGULAR → dadaami (the da at the beginning is from reduplication, a characteristic of class 3 verbs in Sanskrit)

Internal Modification

There are several types of internal modification. An internal modification may be segmental, meaning it changes a sound in the root.

English Example:
STINK + PAST = stank (i becomes a)

An internal modification might be a [suprasegmental] modification. An example would be a change in pitch.

A slightly controversial exponent is subtraction, in which a sound or group of sounds is removed. Some people don't think this happens.