In linguistics a morpheme is the smallest component of a word or other linguistic unit that has semantic meaning. The term is used as part of the branch of linguistics known as morphology (linguistics). A morpheme is composed by phoneme(s) (the smallest linguistically distinctive units of sound) in spoken language and by grapheme(s) (the smallest units of written language) in written language.

The concept of word and morpheme are different: a morpheme may or may not stand alone. One or several morphemes compose a word. A morpheme is free if it can stand alone (ex: "lie" "cake") or bound if it is used exclusively alongside a free morpheme (ex: "im" in impossible). Its actual phonetic representation is the morph with the different morphs ("in-" "im-") representing the same morpheme being grouped as its allomorphs. English example:

The word "unbreakable" has three morphemes: "un-" a bound morpheme; "break" a free morpheme; and "-able" a bound morpheme. "un-" is also a prefix "-able" is a suffix. Both "un-" and "-able" are affixes.

The morpheme plural-s has the morph "-s" /s/ in cats (/kts/) but "-es" /z/ in dishes (/dz/) and even the voiced "-s" /z/ in dogs (/dz/). "-s". These are allomorphs.

Whether or not a word is divided on all available morphemes is debatable. Some morphologists decompose the words completely as it was formed etymologically while others only decompose what there is evidence to decompose in the modern use of the word.

The word "governmental" has either three morphemes: "govern" a free morpheme: "ment" a bound morpheme; and "-al" a bound morpheme. Or depending on the syntactic framework it has two morphemes: "government" and "-al."

The word "predict" has either two morphemes: "pre-" a bound morpheme" and "dict" a bound morpheme or one morpheme: "predict" a free morpheme. Contents 1 Types of morphemes 1.1 Other variants 2 Morphological analysis 3 Changing definitions of Morpheme 4 See also 5 References 6 External links Types of morphemes Free morphemes like town and dog can appear with other lexemes (as in town hall or dog house) or they can stand alone i.e. "free". Bound morphemes like "un-" appear only together with other morphemes to form a lexeme. Bound morphemes in general tend to be prefixes and suffixes. Unproductive non-affix morphemes that exist only in bound form are known as "cranberry" morphemes from the "cran" in that very word. Derivational morphemes can be added to a word to create (derive) another word: the addition of "-ness" to "happy" for example to give "happiness." They carry semantic information. Inflectional morphemes modify a word's tense number aspect and so on without deriving a new word or a word in a new grammatical category (as in the "dog" morpheme if written with the plural marker morpheme "-s" becomes "dogs"). They carry grammatical information. Allomorphs are variants of a morpheme e.g. the plural marker in English is sometimes realized as /-z/ /-s/ or /-z/ Other variants Null morpheme Root morpheme Word stem Morphological analysis

In natural language processing for Japanese Chinese and other languages morphological analysis is a process of segmenting a given sentence into a row of morphemes. It is closely related to Part-of-speech tagging but word segmentation is required for these languages because word boundaries are not indicated by blank spaces. Famous Japanese morphological analysers include Juman ChaSen and Mecab. Changing definitions of Morpheme

In generative grammar the definition of a morpheme depends heavily on whether syntactic trees have morphemes as leafs or features as leafs. Direct surface to syntax mapping LFG leafs are words Direct syntax to semantics mapping Leafs in syntactic trees spell out morphemes: Distributed morphology leafs are morphemes Branches in syntactic trees spell out morphemes:Radical Minimalism and Nanosyntax -leafs are "nano" morpho-syntactic features Given the definition of morpheme as "the smallest meaningful unit" Nanosyntax aims to account for idioms where it is often an entire syntactic tree which contributes "the smallest meaningful unit." An example idiom is "Don't let the cat out of the bag" where the idiom is composed of "let the cat out of the bag" and that might be considered a semantic morpheme which is composed of many syntactic morphemes. Other cases where the "smallest meaningful unit" is larger than a word include some collocations such as "in view of" and "business intelligence" where the words together have a specific meaning. The definition of morphemes also play a significant role in the interfaces of generative grammar in the following theoretical constructs; Event semantics The idea that each productive morpheme must have a compositional semantic meaning (a denotation) and if the meaning is there there must be a morpheme (null or overt). Spell-out The interface where syntactic/semantic structures are "spelled-out" using words or morphemes with phonological content. This can also be thought of as lexical insertion into the syntactics See also Look up morpheme in Wiktionary the free dictionary. Linguistics International Phonetic Alphabet Hybrid word Alternation (linguistics) Theoretical linguistics Marker (linguistics) Morphological parsing Lexicology Greek morphemes Lexeme Morphophonology Chereme Grapheme Phoneme Sememe Floating tone References Spencer Andrew (1992). Morphological Theory. Oxford: Blackwell.  External links Glossary of Reading Terms Comprehensive and searchable morpheme reference Linguistics 001 Lecture 7 Morphology by Prof. Mark Lieberman Morphemes A New Threat to Society: A humorous look at morphemes. Accurate but purposely confuses morphemes with narcotics (i.e. "morphine"). Morpheme Study Aid Pronunciation of the word morpheme