It is an internal change in the form of a word that shows its grammatical function

Word

Form

Morph.

Examples

Noun

Plural

-s

Dog-s, house-s, book-s, keyboard-s, camera-s

Mugs, animals, kids, celphones.

Verb

3rd present. Conjug.

Past simple

Past participle

Present participle

Gerund

-s

-es

-ed (d)

-ing

Sell-s, take-s, speak-s

Runs, jumps, pushes.

Drill-ed, squell-ed, talk-ed

Skied, scattered, listened.

Go-ing, feel-ing, stand-ing

Participating, advocating.

Adjective

Comparative

Superlative

-er

-est

Fast-er, strong-er, old-er

Fast-est, strong-est, old-est.

NOUNS

Type

Morpheme

Examples

Regular

-s

Dogs, houses, books, buses, kids, sons, grandparents, etc.

Irregular

None

Internal irr

-en

Deer, sheep, fish,

Man-men, foot-feet, woman – women

Mouse – mice.

Child-children, ox- oxen.

Foreign

-on -a

-is -es

- ix -ices

-um -a

-us -Ii

Criterion – criteria, phenomenom – phenomena.

Analysis – analyses, crisis – crises

Matrix – matrices, index – indices, appendix- appendices.

Datum- Data, Erratum – errata, medium – media, effluvium – effluvia.

Cactus – Cactii, Terminus – Termini.