Focus (linguistics)


In linguistics, focus is a grammatical category that conveys the part of the sentence that contributes new, non-derivable, or contrastive information. In the English sentence "Mary only insulted BILL", focus is expressed prosodically by a pitch accent on "Bill", which identifies him as the only person whom Mary insulted. By contrast, in the sentence "Mary only INSULTED Bill", the verb "insult" is focused and thus expresses that Mary performed no other actions towards Bill. Focus is a cross-linguistic phenomenon and a major field of study in linguistics. Research on focus spans numerous subfields including phonetics, syntax, semantics, pragmatics, and sociolinguistics.

Functional approaches

Information structure has been described at length by a number of linguists as a grammatical phenomenon. Lexicogrammatical structures that code prominence, or focus, of some information over other information has a particularly significant history dating back to the 19th century. Recent attempts to explain focus phenomena in terms of discourse function, including those by Knud Lambrecht and Talmy Givón, often connect focus with the packaging of new, old, and contrasting information. Lambrecht in particular distinguishes three main types of focus constructions: predicate-focus structure, argument-focus structure, and sentence-focus structure. Focus has also been linked to other more general cognitive processes, including attention orientation.
In such approaches, contrastive focus is understood as the coding of information that is contrary to the presuppositions of the interlocutor. The topic–comment model distinguishes between the topic and what is being said about that topic.

Formalist approaches

Standard formalist approaches to grammar argue that phonology and semantics cannot exchange information directly. Therefore, syntactic mechanisms including features and transformations include prosodic information regarding focus that is passed to the semantics and phonology. Focus may be highlighted either prosodically or syntactically or both, depending on the language. In syntax, this can be done assigning focus markers, as shown in, or by preposing as shown in :
In, focus is marked syntactically with the subscripted ‘f’, which is realized phonologically by a nuclear pitch accent. Clefting induces an obligatory intonation break. Therefore, in, focus is marked via word order and a nuclear pitch accent.
In English, focus also relates to phonology and has ramifications for how and where suprasegmental information such as rhythm, stress, and intonation is encoded in the grammar, and in particular intonational tunes that mark focus. Speakers can use pitch accents on syllables to indicate what word are in focus. New words are often accented while given words are not. The accented word forms the focus domain. However, not all of the words in a focus domain need be accented.. The focus domain can be either broad, as shown in, or narrow, as shown in and :
The question/answer paradigm shown in – has been utilized by a variety of theorists to illustrate the range of contexts a sentence containing focus can be used felicitously. Specifically, the question/answer paradigm has been used as a diagnostic for what counts as new information. For example, the focus pattern in would be infelicitous if the question was ‘Did you see a grey dog or a black dog?’.
In and, the pitch accent is marked in bold. In, the pitch accent is placed on dog but the entire noun phrase a grey dog is under focus. In, the pitch accent is also placed on dog but only the noun dog is under focus. In, pitch accent is placed on grey and only the adjective grey is under focus.
Historically, generative proposals made focus a feature bound to a single word within a sentence. Noam Chomsky and Morris Halle formulated a Nuclear Stress Rule that proposed there to be a relation between the main stress of a sentence and a single constituent. Since this constituent is prominent sententially in a way that can contrast with lexical stress, this was originally referred to as "nuclear" stress. The purpose of this rule was to capture the intuition that within each sentence, there is one word in particular that is accented more prominently because of its importance, which is said to form the nucleus of that sentence.
Focus was later suggested to be a structural position at the beginning of the sentence in Romance languages such as Italian, as the lexical head of a Focus Phrase. Jackendoff, Selkirk, Rooth, Krifka, Schwarzschild argue that focus consists of a feature that is assigned to a node in the syntactic representation of a sentence.
Because focus is now widely seen as corresponding between heavy stress, or nuclear pitch accent, this feature is often associated with the phonologically-prominent element of a sentence.
Sound structure studies of focus are not as numerous, as relational language phenomena tend to be of greater interest to syntacticians and semanticists. Hopwever, that may be changing since a recent study found that focused words and phrases have a higher range of pitch compared to words in the same sentence, and words after the focus in both American English and Mandarin Chinese are also lower than normal in pitch and that 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 variations in pragmatics or timing.
Currently, there are two central themes in research on focus in generative linguistics. First, given what words or expressions are prominent, what is the meaning of some sentence? Rooth, Jacobs, Krifka, and von Stechow claim that there are lexical items and construction specific-rules that refer directly to the notion of focus. Dryer, Kadmon, Marti, Roberts, Schwarzschild, Vallduvi, and Williams argue for accounts in which general principles of discourse explain focus sensitivity. Second, given the meaning and syntax of some sentence, what words or expressions are prominent?

Prominence and meaning

Focus directly affects the semantics, or meaning, of a sentence. Different ways of pronouncing the sentence affects the meaning or what the speaker intends to convey. Focus distinguishes one interpretation of a sentence from other interpretations of the same sentence that do not differ in word order but may differ in the way in which the words are taken to relate to one another. To see the effects of focus on meaning, consider the following examples:
In, accent is placed on Sue. There are two readings of – broad focus shown in and narrow focus shown in :
The meaning of can be summarized as the only thing John did was introduce Bill to Sue. The meaning of can be summarized as the only person to whom John introduced Bill is Sue.
In both and, focus is associated with the focus sensitive expression only. This is known as association with focus. The class of focus sensitive expressions in which focus can be associated with includes exclusives non-scalar additives scalar additives, particularlizers, intensifiers, quantificational adverbs, quantificational determiners, sentential connectives, emotives, counterfactuals, superlatives, negation and generics. It is claimed that focus operators must c-command their focus.

Alternative semantics

In the alternative semantics approach to focus pioneered by Mats Rooth, each constituent has both an ordinary denotation and a focus denotation which are composed by parallel computations. The ordinary denotation of a sentence is simply whatever denotation it would have in a non-alternative-based system, and its focus denotation can be thought of as the set containing all ordinary denotations one could get by substituting the focused constituent for another expression of the same semantic type.
For a sentence such as, the ordinary denotation will be the proposition that is true iff Mary likes Sue. Its focus denotation will be the set of each propositions such that for some contextually relevant individual 'x', that proposition is true iff Mary likes 'x'.
In formal terms, the ordinary denotation of will be as shown below:
  • .
Focus denotations are computed using the alternative sets provided by alternative semantics. In this system, most unfocused items denote the singleton set containing their ordinary denotations.
Focused constituents denote the set of all semantic objects of the same type.
  • , where E is the domain of entities or individuals.
In alternative semantics, the primary composition rule is Pointwise Functional Application. This rule can be thought of as analogous to the cross product.
  • Pointwise Functional Application: If is a constituent with daughters and which are of type and respectively, then
Applying the rule to example would give the following focus denotation if the only contextually relevant individuals are Sue, Bill, Lisa, and Mary
The focus denotation can be "caught" by focus-sensitive expressions like "only" as well as other covert items such as the squiggle operator.

Structured meanings

Following Jacobs and Williams, Krifka argues differently. Krifka claims focus partitions the semantics into a background part and focus part, represented by the pair:
File:KrifkaFocus.jpg|frame|right|The syntactic/semantic tree of the sentence John only introduced f to f.
The logical form of which represented in lambda calculus is:
This pair is referred to as a structured meaning. Structured meanings allow for a compositional semantic approach to sentences that involve single or multiple foci. This approach follows Gottlob Frege's We can access the meaning of an item in focus directly, and 2) Rooth's alternative semantics can be derived from a structured meaning approach but not vice versa. To see Krifka's approach illustrated, consider the following examples of single focus shown in and multiple foci shown in :
Generally, the meaning of can be summarized as John introduced Bill to Sue and no one else, and the meaning of can be summarized as the only pair of persons such that John introduced the first to the second is Bill and Sue.
Specifically, the structured meaning of is:
The background part of the structured meaning is; introd ; and the focus part is s.
Through a form of functional application, the focus part of and is projected up through the syntax to the sentential level. Importantly, each intermediate level has distinct meaning.