Word
A word is a basic element of language that carries meaning, can be used on its own, and is uninterruptible. Despite the fact that language speakers often have an intuitive grasp of what a word is, there is no consensus among linguists on its definition and numerous attempts to find specific criteria of the concept remain controversial. Different standards have been proposed, depending on the theoretical background and descriptive context; these do not converge on a single definition. Some specific definitions of the term "word" are employed to convey its different meanings at different levels of description, for example based on phonological, grammatical or orthographic basis. Others suggest that the concept is simply a convention used in everyday situations.
The concept of "word" is distinguished from that of a morpheme, which is the smallest unit of language that has a meaning, even if it cannot stand on its own. Words are made out of at least one morpheme. Morphemes can also be joined to create other words in a process of morphological derivation. In English and many other languages, the morphemes that make up a word generally include at least one root and possibly some affixes. Words with more than one root are called compound words. Contractions are words formed from multiple words made into one. In turn, words are combined to form other elements of language, such as phrases, clauses, and sentences.
In most languages, the notion of what constitutes a "word" may be learned as part of learning the writing system. This is the case for the English language, and for most languages that are written with alphabets derived from the ancient Latin or Greek alphabets. In English orthography, the letter sequences "rock", "god", "write", "with", "the", and "not" are considered to be single-morpheme words, whereas "rocks", "ungodliness", "typewriter", and "cannot" are words composed of two or more morphemes.
Definitions
Since the beginning of the study of linguistics, numerous attempts at defining what a word is have been made, with many different criteria. However, no satisfying definition has yet been found to apply to all languages and at all levels of linguistic analysis. It is, however, possible to find consistent definitions of "word" at different levels of description. These include definitions on the phonetic and phonological level, that it is the smallest segment of sound that can be theoretically isolated by word accent and boundary markers; on the orthographic level as a segment indicated by blank spaces in writing or print; on the basis of morphology as the basic element of grammatical paradigms like inflection, different from word-forms; within semantics as the smallest and relatively independent carrier of meaning in a lexicon; and syntactically, as the smallest permutable and substitutable unit of a sentence.In some languages, these different types of words coincide and one can analyze, for example, a "phonological word" as essentially the same as "grammatical word". However, in other languages they may correspond to elements of different size. Because of this unclear status, some linguists propose avoiding the term "word" altogether, instead focusing on better defined terms such as morphemes.
Dictionaries categorize a language's lexicon into individually listed forms called lemmas. These can be taken as an indication of what constitutes a "word" in the opinion of the writers of that language. This written form of a word constitutes a lexeme. The most appropriate means of measuring the length of a word is by counting its syllables or morphemes. When a word has multiple definitions or multiple senses, it may result in confusion in a debate or discussion.
Phonology
One distinguishable meaning of the term "word" can be defined on phonological grounds. It is a unit larger or equal to a syllable, which can be distinguished based on segmental or prosodic features, or through its interactions with phonological rules. In Walmatjari, an Australian language, roots or suffixes may have only one syllable but a phonologic word must have at least two syllables. A disyllabic verb root may take a zero suffix, e.g. luwa-ø 'hit!', but a monosyllabic root must take a suffix, e.g. ya-nta 'go!', thus conforming to a segmental pattern of Walmatjari words. In the Pitjantjatjara dialect of the Wati language, another language from Australia, a word-medial syllable can end with a consonant but a word-final syllable must end with a vowel.In most languages, stress may serve a criterion for a phonological word. In languages with a fixed stress, it is possible to ascertain word boundaries from its location.
Many phonological rules operate only within a phonological word or specifically across word boundaries. In Hungarian, dental consonants /d/, /t/, /l/ or /n/ assimilate to a following semi-vowel /j/, yielding the corresponding palatal sound, but only within one word. Conversely, external sandhi rules act across word boundaries. The prototypical example of this rule comes from Sanskrit; however, initial consonant mutation in contemporary Celtic languages or the linking r phenomenon in some non-rhotic English dialects can also be used to illustrate word boundaries.
It is often the case that a phonological word does not correspond to our intuitive conception of a word. The Finnish compound word pääkaupunki 'capital' is phonologically two words because it does not conform to Finnish patterns of vowel harmony within words. Conversely, a single phonological word may be made up of more than one syntactical elements, such as in the English phrase I'll come, where I'll forms one phonological word.
Lexemes
A word can be thought of as an item in a speaker's internal lexicon; this is called a lexeme. However, this may be different from the meaning in everyday speech of "word", since one lexeme includes all inflected forms. The lexeme refers to the singular teapot as well as the plural teapots. There is also the question to what extent should inflected or compounded words be included in a lexeme, especially in agglutinative languages. For example, there is little doubt that in Turkish the lexeme for should include nominative singular ev and plural evler. However, it is not clear if it should also encompass the word evlerinizden 'from your houses', formed through regular suffixation. There are also lexemes such as "black and white" or "do-it-yourself", which, although consisting of multiple words, still form a single collocation with a set meaning.Grammar
Grammatical words are proposed to consist of a number of grammatical elements which occur together in a fixed order and have a set meaning. However, there are exceptions to all of these criteria.Single grammatical words have a fixed internal structure; when the structure is changed, the meaning of the word also changes. In Dyirbal, which can use many derivational affixes with its nouns, there are the dual suffix -jarran and the suffix -gabun meaning "another". With the noun yibi they can be arranged into yibi-jarran-gabun or yibi-gabun-jarran but changing the suffix order also changes their meaning. Speakers of a language also usually associate a specific meaning with a word and not a single morpheme. For example, when asked to talk about untruthfulness they rarely focus on the meaning of morphemes such as -th or -ness.
Semantics
introduced the concept of "Minimal Free Forms" in 1928. Words are thought of as the smallest meaningful unit of speech that can stand by themselves. This correlates phonemes to lexemes. However, some written words are not minimal free forms as they make no sense by themselves. Some semanticists have put forward a theory of so-called semantic primitives or semantic primes, indefinable words representing fundamental concepts that are intuitively meaningful. According to this theory, semantic primes serve as the basis for describing the meaning, without circularity, of other words and their associated conceptual denotations.Features
In the Minimalist school of theoretical syntax, words are construed as "bundles" of linguistic features that are united into a structure with form and meaning. For example, the word "koalas" has semantic features, category features, number features, phonological features, etc.Orthography
In languages with a literary tradition, the question of what is considered a single word is influenced by orthography. Word separators, typically spaces and punctuation marks are common in modern orthography of languages using alphabetic scripts, but these are a relatively modern development in the history of writing. In character encoding, word segmentation depends on which characters are defined as word dividers. In English orthography, compound expressions may contain spaces. For example, ice cream, air raid shelter and get up each are generally considered to consist of more than one word, and so is no one, but the similarly compounded someone and nobody are considered single words.Sometimes, languages which are close grammatically will consider the same order of words in different ways. For example, reflexive verbs in the French infinitive are separate from their respective particle, e.g. se laver, whereas in Portuguese they are hyphenated, e.g. lavar-se, and in Spanish they are joined, e.g. lavarse.
Not all languages delimit words expressly. Mandarin Chinese is a highly analytic language with few inflectional affixes, making it unnecessary to delimit words orthographically. However, there are many multiple-morpheme compounds in Mandarin, as well as a variety of bound morphemes that make it difficult to clearly determine what constitutes a word. Japanese uses orthographic cues to delimit words, such as switching between kanji and the two kana syllabaries. This is a fairly soft rule, because content words can also be written in hiragana for effect, though if done extensively spaces are typically added to maintain legibility. Vietnamese orthography, although using the Latin alphabet, delimits monosyllabic morphemes rather than words.