In linguistics, the focus determines which part of the sentence contributes the most important information. The focus may be highlighted either prosidically or syntactically or both, depending on the language. Although most articles in linguistic theory on focus are devoted to its effects in English, the effects of the relation between prominence and salience has been commented upon not only in the 'topic-comment' division in Korean and Japanese, but also related phenomena in Hungarian, Italian and Russian. Broadly conceived, linguistics is the scientific study of human language, and a linguist is someone who engages in this study(the more accurate term is linguistician but it is too much of a tongue-twister to become generally accepted. ... Sentence, derived from Latin sententia (perception, in the subjective sense of how one feels reality is), has three common meanings: Sentence (linguistics) Sentence (mathematical logic) Open sentence (a term that mathematics teachers attempted to introduce, but not used by mathematicians) Sentence (law) Sentence (music) This is a disambiguation page — a... In linguistics, prosody refers to intonation and vocal stress in speech. ... In linguistics, syntax is the study of the rules, or patterned relations, that govern the way the words in a sentence are arranged. ...

Focus, due to its often uncertain and broadly applied definition, has been analysed in a variety of ways by linguists. Original proposals for focus made it a feature bound to a single word within a sentence. In the Sound Pattern of English by Morris Halle and Noam Chomsky the authors formulated a Nuclear Stress Rule which proposed this relation between the main stress of a sentence and a single constituent. This was to capture the intuition that within each sentence spoken, there is one word in particular that is said more clearly due to its importance. A feature is a concept applied to several fields of linguistics involving the assignment of binary or unary conditions which act as constraints. ...

Focus was later proposed to be a structural position at the beginning of the sentence (or on the left periphery of the syntax) within Romance languages such as Italian, as the lexical head of a Focus Phrase (or FP, following the X-bar theory of phrase structure).

Since this word is 'stressed' sententially in a way that contrasts with lexical stress, this was originally referred to as nuclear stress by Chomsky & Halle. Differences between this original idea of focus and newer conceptions include that focus is not thought any more to be marked on specific words or even positions within a sentence, but focus is widely seen now as the correspondence between heavy stress or pitch accent and informational salience linked to an ongoing discourse.

When focus is used as a feature, one theory in semantics is that it becomes a diacritic marking one version of a sentence (the one with that specific focus) from other interpretations of the sentence which do not vary in word order, but may vary in the way in which the words are taken to relate to each other.

Issues in specifying the stress-focus correspondence lead to a major revision of focus as a set property. This spread focus out amongst a set of adjacent words, while allowing it to retain nuclear stress as a default condition. Since the focus corresponds to the main stress of the sentence, moving focus is possible by either strengthening the stress of nearby words or destressing anaphors, or words which relate to something previously stated and thus which would be efficient not to repeat.

In addition to avoiding the restrictions inherent in marrying focus to a specific ordering of words, the change from the focus (singular) to focal sets and multiple foci allows for a better description of the wide/narrow scope and its relation to semantic concepts of implicature and entailment.

Sound structure (phonological and phonetic) studies of focus are not as numerous, as the lexical-relational aspect of focus tends to make it of greater interest to syntactians and semanticists. But this may be changing: a recent study found that not only do focused words and phrases have a higher range of pitch compared to words in the same sentence but that words following the focus in both American English and Mandarin Chinese were lower than normal in pitch and words before a focus are unaffected. The precise usages of focus in natural language are still uncertain. A continuum of possibilities could possibly be defined between precisely enunciated and staccato styles of speech based on a variety of pragmatic reasons.

Sources

• Cinque, Gugielmo (1993)'A null theory of phrase and compound stress' Linguistic Inquiry 24 pp 239-267.
• Chomsky, Noam & Halle, Morris (1968) Sound Pattern of English, MIT Press.
• Jackendoff, Ray (1972) Semantic Structures, MIT Press.
• Neeleman, Ad & Reinhart, Tanya (1998)'Scrambling & the PF-Interface', The Projection of Arguments, CSLI Publications, pg 309-353.
• Pereltsvaig, Anya (2002) 'Topic and focus as linear notions: evidence from Russian and Italian' Proceedings of the Conference on the Interaction between Syntax and Pragmatics at UCL.
• Rooth, Mats 'A theory of focus interpretation' Natural Language Semantics 1, 75-116.
• Szendrői, Kriszta (2004) 'Focus and the interaction between syntax and pragmatics' Lingua 114.
• Xu, J, Xu, C & Sun, X. (2005)'On the temporal domain of focus' Ms, Yale.