1. Lexical Semantics:
* Word Meaning: Defining the meaning of individual words, including synonyms, antonyms, and hyponyms (words with a more specific meaning than another).
* Word Sense Disambiguation: Determining the correct meaning of a word in context, as words can have multiple meanings.
* Lexical Relations: Examining relationships between words, such as:
* Synonymy: Words with similar meanings (e.g., "happy" and "joyful").
* Antonymy: Words with opposite meanings (e.g., "hot" and "cold").
* Hyponymy: A hierarchical relationship between words, where one word is more specific than another (e.g., "dog" is a hyponym of "animal").
* Meronymy: A part-whole relationship (e.g., "wheel" is a meronym of "car").
2. Sentential Semantics:
* Sentence Meaning: Determining the meaning of a sentence, taking into account the meanings of individual words and their grammatical relationships.
* Truth Conditions: Establishing the conditions under which a sentence is true or false.
* Logical Operators: Analyzing the meaning of logical operators (e.g., "and," "or," "not") in sentences.
* Scope Ambiguity: Resolving ambiguities in the meaning of sentences, such as those arising from the scope of quantifiers (e.g., "Every student loves a teacher").
3. Discourse Semantics:
* Textual Meaning: Analyzing the meaning of a whole text, taking into account the relationships between sentences and paragraphs.
* Reference Resolution: Identifying the referents of pronouns and other words in a text.
* Presuppositions: Understanding the assumptions made by a speaker or writer in a text.
* Implicatures: Recognizing the meanings that are implied but not explicitly stated in a text.
4. Computational Semantics:
* Formal Semantics: Using logic and formal methods to represent and analyze meaning.
* Natural Language Processing (NLP): Applying semantic techniques to tasks such as machine translation, text summarization, and question answering.
* Knowledge Representation: Modeling semantic knowledge using ontologies and knowledge graphs.
5. Pragmatics:
* Context Dependence: Recognizing how meaning is influenced by context, such as the speaker's intentions, the social setting, and shared knowledge.
* Speech Acts: Understanding the different actions that can be performed with language, such as asking a question, making a request, or giving a command.
* Conversational Implicatures: Recognizing the meaning that is implied in a conversation, beyond the literal meaning of the words used.
These features collectively contribute to a comprehensive understanding of how meaning is constructed and interpreted in language.