linguistics Linguistics is the scientific study of human language. It is called a scientific study because it entails a comprehensive, systematic, objective, and precise analysis of all aspects of language, particularly its nature and structure. Linguis ...
, the topic, or theme, of a sentence is what is being talked about, and the comment (rheme or focus) is what is being said about the topic. This division into old vs. new content is called information structure. It is generally agreed that clauses are divided into topic vs. comment, but in certain cases the boundary between them depends on which specific grammatical theory is being used to analyze the sentence. Topic, which is defined by pragmatic considerations, is a distinct concept from grammatical subject, which is defined by syntax. In any given sentence these may be the same, but they need not be. For example, in the sentence "As for the little girl, the dog bit her", the subject is "the dog" but the topic is "the little girl". Topic and subject are also distinct concepts from agent (or actor)—the "doer", which is defined by semantics. In English clauses with a verb in the passive voice, for instance, the topic is typically the subject, while the agent may be omitted or may follow the preposition ''by''. For example, in the sentence "The little girl was bitten by the dog", "the little girl" is the subject and the topic, but "the dog" is the agent. In some languages, word order and other syntactic phenomena are determined largely by the topic–comment (theme–rheme) structure. These languages are sometimes referred to as topic-prominent languages. Korean and Japanese are often given as examples of this.

Definitions and examples

The sentence- or clause-level "topic", or "theme", can be defined in a number of different ways. Among the most common are *the phrase in a clause that the rest of the clause is understood to be about, *a special position in a clause (often at the right or left-edge of the clause) where topics typically appear. In an ordinary English clause, the subject is normally the same as the topic/theme (example 1), even in the passive voice (where the subject is a patient, not an agent: example 2): #''The dog'' bit the little girl. #''The little girl'' was bitten by the dog. These clauses have different topics: the first is about ''the dog'', and the second about ''the little girl''. In English it is also possible to use other sentence structures to show the topic of the sentence, as in the following: *''As for the little girl'', the dog bit her. *''It'' was the little girl ''that the dog bit.'' The case of expletives is sometimes rather complex. Consider sentences with expletives (meaningless subjects), like: *It is raining. *There is some room in this house. *There are two days in the year in which the day and the night are equal in length. In these examples the syntactic subject position (to the left of the verb) is manned by the meaningless expletive ("it" or "there"), whose sole purpose is satisfying the
extended projection principle The extended projection principle (EPP) is a linguistic hypothesis about subjects. It was proposed by Noam Chomsky as an addendum to the projection principle. The basic idea of the EPP is that clauses must contain a noun phrase or determiner p ...
, and is nevertheless necessary. In these sentences the topic is never the subject, but is determined pragmatically. In all these cases, the whole sentence refers to the comment part. The relation between topic/theme and comment/rheme/focus should not be confused with the topic-comment relation in
Rhetorical Structure Theory Rhetorical structure theory (RST) is a theory of text organization that describes relations that hold between parts of text. It was originally developed by William Mann, Sandra Thompson, Christian M.I.M. Matthiessen and others at the University ...
-Discourse Treebank (RST-DT corpus) where it is defined as "a general statement or topic of discussion is introduced, after which a specific remark is made on the statement or topic". For example: " s far as the pound goes, ome traders say a slide toward support at 1.5500 may be a favorable development for the dollar this week.

Realization of topic–comment

Different languages mark topics in different ways. Distinct intonation and word-order are the most common means. The tendency to place topicalized constituents sentence-initially ("topic fronting") is widespread. Topic fronting refers to placing the topic at the beginning of a clause regardless whether it is marked or not. Again, linguists disagree on many details. Languages often show different kinds of grammar for sentences that introduce new topics and those that continue discussing previously established topics. When a sentence continues discussing a previously established topic, it is likely to use pronouns to refer to the topic. Such topics tend to be subjects. In many languages, pronouns referring to previously established topics will show
pro-drop A pro-drop language (from "pronoun-dropping") is a language where certain classes of pronouns may be omitted when they can be pragmatically or grammatically inferable. The precise conditions vary from language to language, and can be quite in ...

In English

In English the topic/theme comes first in the clause, and is typically marked out by intonation as well. English is quite capable of using a topic-prominent formulation instead of a subject-prominent formulation when context makes it desirable for one reason or another. A typical pattern for doing so is opening with a class of prepositions such as ''as for'', ''as regards'', ''regarding'', ''concerning'', ''respecting'', ''on'', ''re'', and others. Pedagogically or expositorily this approach has value especially when the speaker knows that they need to lead the listener's attention from one topic to another in a deftly efficient manner, sometimes actively avoiding misplacement of the focus of attention from moment to moment. But whereas topic-prominent languages might use this approach by default or obligately, in subject-prominent ones such as English it is merely an option that often is not invoked.

In other languages

* In Japanese and
Korean Korean may refer to: People and culture * Koreans, ethnic group originating in the Korean Peninsula * Korean cuisine * Korean culture * Korean language **Korean alphabet, known as Hangul or Chosŏn'gŭl **Korean dialects and the Jeju language ** ...
, the topic is normally marked with a
postposition Prepositions and postpositions, together called adpositions (or broadly, in traditional grammar, simply prepositions), are a class of words used to express spatial or temporal relations (''in'', ''under'', ''towards'', ''before'') or mark various ...
like or 는/은, ''-(n)eun''. * In
Côte d'Ivoire Ivory Coast, also known as Côte d'Ivoire, officially the Republic of Côte d'Ivoire, is a country on the southern coast of West Africa. Its capital is Yamoussoukro, in the centre of the country, while its largest city and economic centre ...
French French (french: français(e), link=no) may refer to: * Something of, from, or related to France ** French language, which originated in France, and its various dialects and accents ** French people, a nation and ethnic group identified with Fran ...
, the topic is marked by the postposition « là ». The topic can be but is not necessarily a noun or a nominal group: « Voiture-là est jolie deh » ; « Aujourd'hui-là il fait chaud » ; « Pour toi-là n'est pas comme pour moi hein » ; « Nous qui sommes ici-là, on attend ça seulement ». * So-called free-word order languages like Russian, Czech and to some certain extent Chinese and
German German(s) may refer to: * Germany (of or related to) **Germania (historical use) * Germans, citizens of Germany, people of German ancestry, or native speakers of the German language ** For citizens of Germany, see also German nationality law **Ge ...
use word order as the primary means, and the topic usually precedes the focus. For example, in some
Slavic languages The Slavic languages, also known as the Slavonic languages, are Indo-European languages spoken primarily by the Slavic peoples and their descendants. They are thought to descend from a proto-language called Proto-Slavic, spoken during the ...
like Czech and Russian, both orders are possible. The order with comment sentence-initial is referred as ''subjective'' (
Vilém Mathesius Vilém Mathesius (, 3 August 1882 – 12 April 1945) was a Czech linguist, literary historian and co-founder of the Prague Linguistic Circle. He is considered one of the founders of structural functionalism in linguistics. Mathesius was the edit ...
invented the term and opposed it to ''objective'') and expresses certain emotional involvement. The two orders are distinguished by intonation. * In
Modern Hebrew Modern Hebrew ( he, עברית חדשה, ''ʿivrít ḥadašá ', , '' lit.'' "Modern Hebrew" or "New Hebrew"), also known as Israeli Hebrew or Israeli, and generally referred to by speakers simply as Hebrew ( ), is the standard form of the He ...
, a topic may follow its comment. For example, the syntactic subject of this sentence is an expletive זה ("ze", lit. "this"): * In
American Sign Language American Sign Language (ASL) is a natural language that serves as the predominant sign language of Deaf communities in the United States of America and most of Anglophone Canada. ASL is a complete and organized visual language that is expre ...
, a topic can be declared at the beginning of a sentence (indicated by raised eyebrows and head tilt) describing the object, and the rest of the sentence describes what happens to that object.

Practical applications

The main application of the topic-comment structure is in the domain of speech technology, especially the design of embodied conversational agents (intonational focus assignment, relation between information structure and posture and gesture). There were some attempts to apply the theory of topic/comment for information retrieval and automatic summarization.


The distinction between subject and topic was probably first suggested by
Henri Weil Henri Weil (August 27, 1818 – November 5, 1909) was a French philologist. Biography Born to a Jewish family in Frankfurt, he was educated at the universities of Bonn, Berlin, and Leipzig. He went to France, and continued his studies at Paris, ...
in 1844. He established the connection between information structure and word order.
Georg von der Gabelentz Hans Georg Conon von der Gabelentz (16 March 1840 – 11 December 1893) was a German general linguist and sinologist. His (1881), according to a critic, "remains until today recognized as probably the finest overall grammatical survey of the Cla ...
distinguished psychological subject (roughly topic) and psychological object (roughly focus). In the
Prague school The Prague school or Prague linguistic circle is a language and literature society. It started in 1926 as a group of linguists, philologists and literary critics in Prague. Its proponents developed methods of structuralist literary analysis and ...
, the dichotomy, termed topic–focus articulation, has been studied mainly by
Vilém Mathesius Vilém Mathesius (, 3 August 1882 – 12 April 1945) was a Czech linguist, literary historian and co-founder of the Prague Linguistic Circle. He is considered one of the founders of structural functionalism in linguistics. Mathesius was the edit ...
, Jan Firbas, František Daneš, Petr Sgall and Eva Hajičová. They have been concerned mainly by its relation to intonation and word-order. Mathesius also pointed out that the topic does not provide new information but connects the sentence to the context. The work of
Michael Halliday Michael Alexander Kirkwood Halliday (often M. A. K. Halliday; 13 April 1925 – 15 April 2018) was a British linguist who developed the internationally influential systemic functional linguistics (SFL) model of language. His grammatical descrip ...
in the 1960s is responsible for developing linguistic science through his systemic functional linguistics model for English.M.A.K.Halliday, An Introduction to Functional Grammar, 2nd ed. London: Arnold, 1994.

See also

* Focus (linguistics) *
Predicate (grammar) The term predicate is used in one of two ways in linguistics and its subfields. The first defines a predicate as everything in a standard declarative sentence except the subject, and the other views it as just the main content verb or associate ...
* Textual function (systemic functional linguistics) * Thematic equative *
Topicalization Topicalization is a mechanism of syntax that establishes an expression as the sentence or clause topic by having it appear at the front of the sentence or clause (as opposed to in a canonical position further to the right). This involves a phrasal ...
* Topic marker * Topic-prominent language


Further reading

* Givón, Talmy. 1983a. '' Topic continuity in discourse: A quantitative cross-language study.'' Amsterdam: Arshdeep Singh. * Hajičová, Eva, Partee, Barbara H., Sgall, Petr. 1998. ''Topic–Focus Articulation, Tripartite Structures, and Semantic Content.'' Studies in Linguistics and Philosophy 71. Dordrecht: Kluwer. (ix + 216 pp.
* Halliday, Michael A. K. 1967–68. "Notes on transitivity and theme in English" (Part 1–3). ''Journal of Linguistics'', 3 (1). 37–81; 3 (2). 199–244; 4(2). 179–215. * Halliday, Michael A. K. (1970). "Language structure and language function." In J. Lyons (Ed.), ''New Horizons in Linguistics''. Harmondsworth: Penguin, 140–65. * Hockett, Charles F. 1958.
A Course in Modern Linguistics
'. New York: The Macmillan Company. (pp. 191–208) * Mathesius, Vilém. 1975. ''A Functional Analysis of Present Day English on a General Linguistic Basis''. edited by Josef Vachek, translated by Libuše Dušková. The Hague – Paris: Mouton. * Kadmon, Nirit. 2001. ''Pragmatics Blackwell Publishers''. Blackwell Publishers. * Lambrecht, Knud. 1994. ''Information structure and sentence form.'' Cambridge: Cambridge University Press. * Li, Charles N., Thompson, Sandra A. 1976. ''Subject and Topic: A New Typology of Languages'', in: Li, Charles N. (ed.) Subject and Topic, New York/San Francisco/London: Academic Press, 457–90. * Payne, Thomas E. 1997.
Describing morphosyntax: A guide for field linguists
'' Cambridge: Cambridge University Press. * Von der Gabelentz, Georg. 1891. ''Die Sprachwissenschaft, ihre Aufgaben, Methoden und bisherigen Ergebnisse.'' Leipzig: T.O. Weigel Nachfolger. * Weil, Henri. 1887. ''De l'ordre des mots dans les langues anciennes comparées aux langues modernes: question de grammaire générale.'' 1844. Published in English as ''The order of words in the ancient languages compared with that of the modern languages.''

External links

SFG page: theme
– an explanation, for beginners, of theme in
systemic functional grammar Systemic functional grammar (SFG) is a form of grammatical description originated by Michael Halliday. It is part of a social semiotic approach to language called ''systemic functional linguistics''. In these two terms, ''systemic'' refers to ...
by Alvin Leong
Iliev, Iv. The Russian Genitive of Negation and Its Japanese Counterpart. International Journal of Russian Studies. 1, 2018
{{DEFAULTSORT:Topic and comment Systemic functional linguistics Word order Linguistics Dichotomies Semantics