Topic vs Focus

How information structure works

Every utterance does two jobs. It locates a piece of common ground — the entity the conversation is currently centred on — and it adds something to it. Linguists call the first part the topic and the second the focus. The split is informational, not syntactic: it cuts across subjects, objects and adjuncts.

Consider an exchange. Where did John go? The questioner has stipulated John as the topic; what is unknown — the destination — is the focus. The natural answer is John went to PARIS, with Paris bearing the pitch accent. Ask a different question — Who went to Paris? — and the focus shifts to JOHN went to Paris. Same syntax, different information structure.

This split has consequences across the grammar. Topics tend to be definite, given, and pronominal once established. Focus tends to be indefinite, new, and prosodically prominent. Languages exploit different combinations of three signalling channels:

1. Morphology — particles like Japanese wa for topic, Korean nun, Tagalog ang.
2. Syntax — dedicated positions: topic to the left edge, focus to a preverbal slot or a cleft.
3. Prosody — pitch accent, deaccenting, intonational phrasing.

English leans on the third channel. Mandarin and Japanese use all three. Hungarian uses the first two heavily. The cross-linguistic variation is where the discourse interface is most visible.

Why this matters

• Discourse coherence. Mismatched topic/focus is the most common source of "this paragraph doesn't flow."
• Translation. Topic-prominent languages re-package information; literal translation often shifts the topic.
• Question-answer matching. A wh-question stipulates the focus position; a felicitous answer fills exactly that slot.
• Prosody and reading. Misplaced pitch accent in TTS output makes machine speech feel robotic.
• Second language acquisition. English speakers underuse topicalization in Mandarin; Mandarin speakers overuse English clefts.
• Information structure and writing. Topic continuity drives paragraph flow; focus articulation drives emphasis.
• Politeness and pragmatics. Choice of topic signals what the speaker presupposes the hearer already knows.

Topic vs focus

	Topic	Focus
Definition	What the sentence is about	What the sentence asserts
Information status	Given, presupposed	New, asserted
Definiteness	Usually definite	Often indefinite
Position (English)	Sentence-initial; "as for X"	Anywhere; carries pitch accent
Marker (Japanese)	は (wa)	が (ga) for new subject; prosody
Marker (Mandarin)	Sentence-initial slot before subject	Cleft 是…的; focus particles 只, 也
Marker (Hungarian)	Left periphery	Immediately preverbal slot
Anaphor preference	Becomes pronominal after introduction	Typically full noun phrase
Question correlate	Stipulated by the question	Answer to the wh-word

Cross-linguistic patterns

Mandarin Chinese is the textbook topic-prominent language. The basic clause is topic plus comment, and the topic need not be a syntactic argument of the verb:

这本书我看了。
zhè běn shū   wǒ kàn le.
this CL  book   I read PRF
"This book, I have read." (lit. "This book, I read.")

Zhè běn shū is the topic; the comment wǒ kàn le "I have read it" follows. The book is not the grammatical subject — that is I — but it is what the sentence is about. English allows the same word order with prosodic licensing (This book, I've read) but treats it as marked, while Mandarin treats it as the unmarked option.

Mandarin also licenses dangling topics with no syntactic role at all: 象，鼻子很长 "elephants, the nose is very long." The topic elephants sets the frame; the comment is about the nose.

Japanese uses the particle wa to mark topic and the particle ga to mark a new or focused subject:

象は鼻が長い。
zō wa hana ga nagai.
elephant TOP nose NOM long
"As for elephants, the nose is long."

The contrast is sharp. Tanaka-san wa gakusei desu "As for Tanaka, (he) is a student" presupposes the listener knows who Tanaka is. Tanaka-san ga gakusei desu "It is Tanaka who is a student" introduces Tanaka as the answer to "who is a student?" The wa/ga choice is the most studied topic/focus contrast outside Indo-European.

Hungarian has a dedicated preverbal focus position. Any contrastively focused phrase must move there:

JÁNOS ment Párizsba.
JÁNOS went-PAST Paris-to
"It was János who went to Paris."

The same words in a different order would be neutral or give a different focus. Other languages with preverbal focus include Basque and many Bantu languages.

English relies primarily on prosody. Pitch accent on a constituent picks it out as focused; deaccenting signals givenness. Syntactic focus devices include the it-cleft (It was John who left), the pseudo-cleft (What John did was leave) and inversion (Down the hill rolled the ball).

French uses dislocation: Jean, il est parti "John, he left" — the dislocated topic is resumed by a clitic pronoun. Spoken French uses dislocation so often that the apparent doubling is the norm rather than the exception.

Worked examples

Question-answer congruence. Q: What did John buy? The wh-word marks the focus slot. Felicitous answers: He bought a CAR (focus on object) or A CAR. Infelicitous: JOHN bought a car — that would answer "Who bought a car?" instead.

Mandarin topic chain. 这本书，我买了，∅ 看了三天，∅ 然后送给了朋友. "This book, I bought it, ∅ read it for three days, ∅ then gave it to a friend." A single topic licenses three comments without re-mention.

Japanese contrastive wa. 魚は食べるが、肉は食べない. "Fish (TOPIC), I eat, but meat (TOPIC), I don't eat." The same particle that marks topic also marks contrastive topic when used twice.

English contrastive focus. I didn't say MARY left, I said JANE left. Capital letters represent the pitch accent. Contrastive focus presupposes an alternative set — here, the set of people whose departure was at issue.

Cleft for focus. It was on TUESDAY that the meeting happened. The cleft construction unambiguously focuses Tuesday; everything in the relative clause is presupposed.

As-for topicalization. As for the deficit, no one wants to discuss it. The "as for" prefix signals an English topic, often used to switch from one topic to another in a paragraph.

Related variants

• Theme-rheme. The Prague School term, popularized for English by Halliday. Theme = clause-initial slot; rheme = the rest. Closely tied to topic-comment but defined positionally.
• Aboutness vs given. Some linguists distinguish aboutness topics (what the sentence is about) from familiarity topics (already in the discourse). Reinhart (1981) defended the aboutness definition.
• Stage topics. Spatial or temporal frames like In Paris, it always rains — topic-like setting for the predicate.
• Frame-setting topics. Hungarian and Korean have a dedicated slot for these; English uses concerning, regarding.
• Information focus vs identificational focus. É. Kiss (1998) distinguishes new-information focus (no exhaustivity) from identificational focus (exhaustive, contrastive). Hungarian preverbal focus is identificational.
• Verum focus. Focus on the polarity itself: I DID lock the door asserts the truth of the proposition against doubt.

Common pitfalls

• Equating topic with subject. They overlap in subject-prominent languages but are independent dimensions. A subject can be focused; an object can be topicalized.
• Treating focus as merely emphasis. Focus is structural — it picks out an alternative set. Emphasis is one way of realizing it.
• Translating Japanese wa as "the." Definiteness and topicality interact, but wa marks information status, not definiteness.
• Overusing English clefts in translation. Mandarin neutral focus needs only prosody in English; rendering it as a cleft over-marks the focus.
• Forgetting that questions stipulate focus. A felicitous answer must place new information where the wh-word was — mismatch produces awkwardness.
• Ignoring contrastive topics. Japanese wa, Mandarin word order and English I-topicalization all license contrastive topics, where two topics are paired against each other.