Topic and comment

Inlinguistics,thetopic,ortheme,of asentenceis what is being talked about, and thecomment(rhemeorfocus) is what is being said about the topic. This division into old vs. new content is calledinformation structure.It is generally agreed thatclausesare divided into topic vs. comment, but in certain cases the boundary between them depends on which specificgrammatical theoryis being used to analyze the sentence.

The topic of a sentence is distinct from the grammaticalsubject.The topic is defined bypragmaticconsiderations, that is, thecontextthat provides meaning. The grammatical subject is defined bysyntax.In any given sentence the topic and grammatical subject 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 being what is being talked about and thesubjectbeing what is doing the action can, also, be distinct concepts from the conceptagent(or actor)—the "doer", which is defined bysemantics,that is, by the contextual meaning of the sentence in the paragraph. In English clauses with averbin thepassive voice,for instance, the topic is typically the subject, while the agent may be omitted or may follow the prepositionby.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 othersyntactic phenomenaare determined largely by the topic–comment (theme–rheme) structure. These languages are sometimes referred to astopic-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 dogbit the little girl.
The little girlwas bitten by the dog.

These clauses have different topics: the first is aboutthe dog,and the second aboutthe 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.
Itwas the little girlthat the dog bit.

The case ofexpletivesis 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 theextended projection principle,and is nevertheless necessary. In these sentences the topic is never the subject, but is determinedpragmatically.In all these cases, the whole sentence refers to the comment part.^[1]

The relation between topic/theme and comment/rheme/focus should not be confused with the topic-comment relation inRhetorical Structure Theory-DiscourseTreebank(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: "[As far as the pound goes,] [some traders say a slide toward support at 1.5500 may be a favorable development for the dollar this week.]"^[2]^[3]

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.^[4]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 showpro-drop.

In English

In English the topic/theme comes first in the clause, and is typically marked out by intonation as well.^[5]

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 witha class of prepositions such as:as for,as regards,regarding,concerning,respecting,on,re,and others.Pedagogicallyorexpositorilythis approach has value especially when the speaker knows that they need tolead the listener's attentionfrom 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

InJapaneseandKorean,the topic is usually marked with apostpositionsuch as-wa(は)or 는/은,-(n)eunrespectively, which comes after the noun or phrase that is being topicalized.
InCôte d'Ivoire French,the topic is marked by the postposition "là". The topic can be, but is not necessarily a noun or a nominal group, for example: « Voiture-là est jolie deh » ( "That car is pretty" ); « Aujourd'hui-là il fait chaud » ( "It's hot on that day" ); « Pour toi-là n'est pas comme pour moi hein » ( "For you it's not the same as for me, huh" ); and « Nous qui sommes ici-là, on attend ça seulement » ( "We who are here, we are waiting for that only" ).
So-calledfree word orderlanguages such asRussian,Czech,and to some certain extentChineseandGerman,use word order as the primary means, and the topic usually precedes the focus. For example, in someSlavic languagessuch as Czech and Russian, both orders are possible. The order with the comment sentence-initial is referred to assubjective(Vilém Mathesiusinvented the term and opposed it toobjective) and expresses certain emotional involvement. The two orders are distinguished by intonation.
InModern Hebrew,a topic may follow its comment. For example, the syntactic subject of this sentence is an expletive זה ( "ze", lit. "this" ):

זה

ze

this

מאד

meʾod

very

מענין

meʿanyen

interesting

הספר

ha-sefer

book

הזה

ha-ze

this

"This book is very interesting."

InAmerican Sign Language,a topic can be declared at the beginning of a sentence (indicated by raised eyebrows and head tilt) describing the referent, and the rest of the sentence describes what happens to that referent.

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).^[6]There were some attempts to apply the theory of topic/comment for information retrieval^[7]and automatic summarization.^[8]

History

The distinction between subject and topic was probably first suggested byHenri Weilin 1844.^[9]He established the connection betweeninformation structureand word order.Georg von der Gabelentzdistinguishedpsychological subject(roughly topic) andpsychological object(roughly focus). In thePrague school,the dichotomy, termedtopic–focus articulation,has been studied mainly byVilém Mathesius,^[10]Jan Firbas,František Daneš,Petr SgallandEva 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 ofMichael Hallidayin the 1960s is responsible for developing linguistic science through hissystemic functional linguisticsmodel for English.^[11]

References

^Michael Gotze, Stephanie Dipper, and Stavros Skopeteas. 2007. Information Structure in Cross-Linguistic Corpora: Annotation Guidelines for Phonology, Morphology, Syntax, Semantics, and Information Structure. Interdisciplinary Studies on Information Structure (ISIS), Working papers of the SFB 632, Vol. 7.
^L. Carlson and D. Marcu, “Discourse tagging reference manual,” ISI Technical Report ISI-TR-545, vol. 54, 2001.
^L. Ermakova and J. Mothe. 2016. Document re-ranking based on topic-comment structure. In X IEEE International Conference RCIS, Grenoble, France, June 1–3, 2016. 1–10.
^D. Bring, Topic and Comment. Cambridge University Press, 2011, three entries for: Patrick Colm Hogan (ed.) The Cambridge Encyclopedia of the Language Sciences. Cambridge: Cambridge University Press.
^MAK Halliday (1994).An introduction to functional grammar,2nd ed., Hodder Arnold: London, p. 37
^Cassell, Justine, ed. Embodied conversational agents. MIT press, 2000.
^A. Bouchachia and R. Mittermeir, “A neural cascade architecture for document retrieval,” in Neural Networks, 2003. Proceedings of the International Joint Conference on, vol. 3. IEEE, 2003, pp. 1915–1920.
^L. Ermakova, J. Mothe, A. Firsov. A Metric for Sentence Ordering Assessment Based on Topic-Comment. Structure, in ACM SIGIR, Tokyo, Japan, 07/08/2017-11/08/2017
^H. Weil, De l’ordre des mots dans les langues anciennes compares aux langues modernes: question de grammaire gnrale. Joubert, 1844.
^V. Mathesius and J. Vachek, A Functional Analysis of Present Day English on a General Linguistic Basis, ser. Janua linguarum: Series practica / Ianua linguarum / Series practica. Mouton, 1975.
^M.A.K.Halliday, An Introduction to Functional Grammar, 2nd ed. London: Arnold, 1994.

External links

SFG page: theme– an explanation, for beginners, of theme insystemic functional grammarby Alvin Leong
Iliev, Iv. The Russian Genitive of Negation and Its Japanese Counterpart. International Journal of Russian Studies. 1, 2018

[1] Michael Gotze, Stephanie Dipper, and Stavros Skopeteas. 2007. Information Structure in Cross-Linguistic Corpora: Annotation Guidelines for Phonology, Morphology, Syntax, Semantics, and Information Structure. Interdisciplinary Studies on Information Structure (ISIS), Working papers of the SFB 632, Vol. 7.

[2] L. Carlson and D. Marcu, “Discourse tagging reference manual,” ISI Technical Report ISI-TR-545, vol. 54, 2001.

[3] L. Ermakova and J. Mothe. 2016. Document re-ranking based on topic-comment structure. In X IEEE International Conference RCIS, Grenoble, France, June 1–3, 2016. 1–10.

[4] D. Bring, Topic and Comment. Cambridge University Press, 2011, three entries for: Patrick Colm Hogan (ed.) The Cambridge Encyclopedia of the Language Sciences. Cambridge: Cambridge University Press.

[5] MAK Halliday (1994).An introduction to functional grammar,2nd ed., Hodder Arnold: London, p. 37

[6] Cassell, Justine, ed. Embodied conversational agents. MIT press, 2000.

[7] A. Bouchachia and R. Mittermeir, “A neural cascade architecture for document retrieval,” in Neural Networks, 2003. Proceedings of the International Joint Conference on, vol. 3. IEEE, 2003, pp. 1915–1920.

[8] L. Ermakova, J. Mothe, A. Firsov. A Metric for Sentence Ordering Assessment Based on Topic-Comment. Structure, in ACM SIGIR, Tokyo, Japan, 07/08/2017-11/08/2017

[9] H. Weil, De l’ordre des mots dans les langues anciennes compares aux langues modernes: question de grammaire gnrale. Joubert, 1844.

[10] V. Mathesius and J. Vachek, A Functional Analysis of Present Day English on a General Linguistic Basis, ser. Janua linguarum: Series practica / Ianua linguarum / Series practica. Mouton, 1975.

[11] M.A.K.Halliday, An Introduction to Functional Grammar, 2nd ed. London: Arnold, 1994.

[1]

[2]

[3]

[4]

[5]

[6]

[7]

[8]

[9]

[10]

[11]