morpheme
smallest linguistic unit within a word that can carry a meaning
affix
morpheme that is attached to a word stem to form a new word
root
indivisible part of word that does not have any affix, may have a meaning and be usable alone or not, and may comprise multiple "radical" forms
clitic
morpheme with syntactic characteristics of a word but with phonological dependence on another word; e.g. ⟨-’m⟩ in ⟨I’m⟩ or ⟨-’ve⟩ in ⟨I’ve⟩; the possessive ⟨-’s⟩, the article ⟨a(n)⟩, and the infinitive marker ⟨to⟩ are sometimes considered clitics
marker
free or bound morpheme that indicates the grammatical function of the marked word, phrase, or sentence
thematic vowel
vowel placed before the ending of a Proto-Indo-European word
free morpheme
morpheme that can stand alone; morpheme that is not a bound morpheme
bound morpheme
morpheme that cannot be used independently
linking morpheme
morpheme inserted in compound words, e.g. -o- in ‘speedometer’, -s- in ‘sportsman’
pro-form
word or form that substitutes for another word, broader scope than pronoun
proto-
prefix
Semitic root
abstract consonant-only roots which are the traditional basis for morphological derivation in the Semitic languages and some other Afroasiatic (Hamitic) languages
null morpheme
morpheme whose realization is not reflected in pronunciation or orthography
functional morpheme
morpheme whose only role is to mark grammatical function; antonym of content morpheme
content morpheme
morpheme that conveys meaning rather than merely marking grammatical function; antonym of functional morpheme