Semantics

Semantics is the study of what words and sentences mean. It looks at how we understand the ideas behind words and how those ideas come together to make the meaning of whole sentences. This helps us see the difference between what a word points to in the world and the ideas we have about it.

There are many parts to semantics. Some parts study how single words have meaning, while others look at how whole sentences get their meaning by putting words together in certain ways. Some parts of semantics even use math and logic to understand meaning better, and others look at how our minds help us understand language.

People have been interested in meaning for a very long time, but semantics became its own area of study in the 1800s. It is important for fields like computer science, psychology, and logic because understanding meaning helps us use language better and build smart machines that can understand us.

Definition and related fields

Semantics is the study of meaning in languages. It looks at what meaning is and how it works. It shows how expressions are made from smaller parts like morphemes, words, clauses, sentences, and texts, and how these parts affect each other’s meaning. Semantics can look at one language, like English, or at meaning in all languages. It tries to understand how meaning works without saying what meaning people should use with certain words.

Semantics looks at how words connect to ideas in our minds and to things in the world. It also looks at how different parts of language, like sounds, rules for putting words together, and how we use language to talk to each other, all relate to meaning. Other areas like phonology, syntax, and pragmatics study different parts of language. Semantics is also linked to etymology, which studies how words change over time.

Basic concepts

Semantics is the study of meaning in language. It looks at how words and sentences carry meaning and how we understand them. For example, dictionaries explain word meanings using other words, like saying a ram is an adult male sheep.

Meaning can be studied in different ways. The meaning of individual words is called lexical semantics. The meaning of whole sentences is part of phrasal semantics. Sometimes, how we use words in real situations, like when we use irony, changes their meaning too.

One important idea in semantics is the difference between sense and reference. Reference is what a word points to, like how morning star and evening star both refer to the planet Venus. Sense is how we think about that reference. Even though they refer to the same thing, their senses are different. Understanding both sense and reference helps us grasp the full meaning of expressions.

Another key idea is compositionality, which says the meaning of a sentence comes from the meanings of its parts and how they are put together. For example, to understand "Zuzana owns a dog," we need to know what Zuzana, owns, a, and dog mean and how they fit together.

Truth is also important in semantics. A true statement matches how the world really is. The truth conditions of a statement are the situations where it would be true. For the sentence "it is raining outside" to be true, it must actually be raining.

The semiotic triangle shows how language, thoughts, and the world are connected. It explains that words don’t directly point to things in the world. Instead, they connect through our thoughts. For example, the word apple doesn’t directly mean a fruit; it makes us think of a fruit, which then connects to the real fruit.

Other ideas in semantics include semantic roles, which describe a word’s job in a sentence, and lexical relations, which show how words relate to each other, like synonyms (car and automobile) and antonyms (alive and dead). Context — where and when a word is used — also changes its meaning.

Branches

Lexical semantics

Main article: Lexical semantics

Lexical semantics is the study of word meaning. It looks at how words get their meaning and how they relate to each other, such as being synonyms or opposites. Words are grouped based on shared features, like physical objects versus ideas. This helps organize words into categories.

Lexical semantics can be split into two approaches. Semasiology looks at words to see what they mean, while onomasiology starts with a concept and finds the words that express it.

Phrasal semantics

Phrasal semantics studies how sentences get their meaning. It looks at how the meaning of a whole sentence comes from the meanings of its parts, like subjects, predicates, and arguments. For example, in "Mary hit the ball," Mary is the subject, hit is the predicate, and the ball is the argument.

Verbs often connect different parts of a sentence to build meaning. Other parts, like adjectives, change the meaning of other words. Tools like parse trees help show how sentence parts fit together.

Formal semantics

Main article: Formal semantics (natural language)

Formal semantics uses logic and math to study meaning in everyday language. It tries to create clear rules to explain how language shows the world. Words point to objects, and sentences talk about events or situations, which can be true or false based on the world.

Formal semantics also looks at how language handles ideas like quantity, time, and possibility. It uses special methods to explain how sentences work together to create meaning.

Cognitive semantics

Main article: Cognitive semantics

Cognitive semantics studies meaning from a thinking person's point of view. It sees language as tied to how we understand the world. It looks at how our minds organize ideas about space, time, and actions.

This area also studies how we group things in our minds and how our bodies affect how we understand language. It looks at how words are understood based on the ideas they are connected to.

Others

Conceptual semantics studies how we think about the world to understand meaning. It looks at how our thoughts, sensing, and doing are linked.

Computational semantics looks at how computers can understand language meaning. It uses math and logic to solve problems like figuring out meaning from parts of sentences.

Cultural semantics studies how culture affects meaning. It looks at how meanings change because of things like customs and beliefs.

Pragmatic semantics studies how the situation affects meaning. It looks at how who is talking and what they know changes what words mean.

Theories of meaning

Theories of meaning help us understand what meaning is, what meaning an expression has, and how we connect expressions to their meaning.

Referential theories say that the meaning of an expression is the thing it points to. For example, the meaning of the name George Washington is the person with that name. General terms, like cat, refer to all cats. However, these theories face challenges, like how names such as Pegasus or Santa Claus have meaning even though they don’t refer to real things. To solve such problems, some theories suggest that meaning depends on context or on what could be true in different situations.

Ideational theories focus on the thoughts and intentions of the person using language. One idea is that words stand for thoughts in our minds. For example, the word dog represents the idea people have of dogs. Another view is that meaning comes from the speaker’s intention. For instance, if someone says, "there is a garage around the corner" while you’re looking for petrol, they mean you can find petrol there, even if they don’t say it directly.

History

Semantics, the study of meaning in language, began in ancient times as part of philosophy and logic. In ancient Greece, Plato looked at how names relate to things. Aristotle wrote about how words connect to ideas in our minds, which then point to real things. The Stoics added to these ideas by studying different types of words and their roles in sentences.

In ancient India, thinkers explored how words help us understand things. In ancient China, others studied how names help us make moral choices.

During the Middle Ages, thinkers like Augustine and Boethius built on these early ideas. Peter Abelard focused more on what whole sentences mean rather than just individual words.

In the 19th century, semantics became its own area of study. Important figures like Christian Karl Reisig and Michel Bréal helped shape the field. In the 20th century, developments by thinkers like Alfred Tarski and Richard Montague advanced our understanding of how meaning works in formal languages.

In various disciplines

Logic

Logicians study how we reason correctly. They create special languages to test if arguments make sense. These languages have rules that explain what each part means. For example, in a special language, we can say "Bertie is a dog" using letters and symbols. This helps us see if statements are true or false based on clear rules.

Computer science

In computer science, semantics is about what a program does when it runs. Different ways to write the same instruction can lead to the same result. For example, in JavaScript, i += 1 and i = i + 1 both increase the number stored in i by one. Some semantics look at errors that happen when writing code, like using the wrong type of data. Other semantics study what happens when the program is running, such as how each step changes the computer's state.

Psychology

Psychological semantics looks at how people understand meaning. It studies how our minds store and use the meanings of words and ideas. It also looks at how we learn new words, understand sentences we've never heard, and deal with confusing phrases. A key idea is semantic memory, which holds general knowledge about words and facts, unlike episodic memory, which remembers personal experiences. Understanding language depends on this stored knowledge of meanings.