Information Structure in Linguistics
In the study of linguistics, information structure refers to how speakers organize the content of their utterances to convey meaning effectively. It is not merely about the grammatical correctness of a sentence, but about how information is packaged to signal what is already known to the listener and what is being introduced as new knowledge.
Focus and Background
Focus is a grammatical category used to indicate that a specific part of an utterance provides new, contrastive, or non-derivable information. In practical terms, focus tells the listener which part of the sentence is the most important piece of new information.
Some linguistic theories, notably those aligned with the work of Mats Rooth, connect focus to alternative semantics. This theory suggests that focus is linked to the presence of alternatives. For example, in the exchange "When did Jane sell the book?" followed by the answer "She sold the book YESTERDAY," the word "yesterday" receives the focus. This is because it could be substituted with other time periods, such as "today" or "last week," while still functioning as a valid answer to the question.
While focus is relatively distinct, background is more complex to define. It is not simply the opposite of focus. According to the framework provided by Daniel P. Hole, focus is a relational notion; the entity that the focus relates to is defined as its background or presupposition.
[ไม่มีภาพประกอบ]Topic and Comment
Another fundamental division in information structure is the relationship between the topic (also known as the theme) and the comment (also known as the rheme or, in some contexts, the focus).
- Topic: What the sentence is talking about.
- Comment: What is being said about that topic.
While most linguists agree that clauses are divided this way, the exact boundary between topic and comment varies by grammatical theory. In some languages, such as Japanese and Korean, the topic is grammaticalized, meaning it is marked by a specific morpheme (a smallest unit of meaning) attached to the topic word.
In languages like English that lack specific topic-markers, linguists use diagnostics to distinguish between different types of topics, such as "aboutness" topics and "contrastive" topics. These diagnostics involve testing the "felicity" (appropriateness) of following a discourse with phrases like "About x...", "Speaking of x...", or "As for x...", or by asking questions such as "What about x?" to determine how topical a specific element is within a context.
Given and New Information
The distinction between given and new information describes the status of knowledge within a conversation. Information is considered "given" if it is already common knowledge or has been mentioned previously in the discourse, making it anaphorically recoverable (able to be identified by referring back to a previous mention).
Some theories, such as Roger Schwarzschild's GIVENness Constraint, propose that any part of a sentence that is not marked as focus must be given information. Conversely, information that is not given—meaning it is textually and situationally non-derivable—is classified as new.
[ไม่มีภาพประกอบ]Key Facts
- Focus highlights new or contrastive information and is often linked to alternative semantics.
- Background is the entity to which the focus relates, often viewed as a presupposition.
- Topic (Theme) is the subject of discussion, while the Comment (Rheme) provides information about that subject.
- Japanese and Korean use specific morphemes to mark the topic grammatically.
- Given information is already known or previously mentioned; new information cannot be derived from the current context.
| Concept Pair | Primary Function | Key Characteristic |
|---|---|---|
| Focus vs. Background | Highlighting new/contrastive data | Relational; based on alternatives |
| Topic vs. Comment | Defining the subject and the statement | Can be grammaticalized (e.g., Japanese) |
| Given vs. New | Tracking knowledge state | Based on common knowledge or prior mention |
Frequently Asked Questions
What is the difference between focus and topic?
The topic is what the sentence is about (the theme), whereas the focus is the specific part of the utterance that provides new or contrastive information (often part of the comment).
How do languages like Japanese handle topics differently than English?
Japanese and Korean have designated topic-marker morphemes that explicitly mark the topic of a sentence, whereas English relies on word order and contextual diagnostics.
What does "anaphorically recoverable" mean?
It refers to information that is considered "given" because it can be recovered by referring back to something previously mentioned in the discourse.
What is the GIVENness Constraint?
Proposed by Roger Schwarzschild, this theory suggests that all constituents in a sentence that are not marked as focus must be given information.
How does alternative semantics explain focus?
It suggests that a word is in focus because it could be replaced by other possible alternatives (e.g., replacing "yesterday" with "today") while still answering the original question.