Lemma (morphology) facts for kids
Have you ever wondered how dictionaries list words? When you look up a word like "running," you'll usually find it under "run." That's because "run" is the lemma of "running."
A lemma is the basic form of a word. It's the form you'd typically find in a dictionary. Think of it as the "main" word that represents all its different versions. For example, "break," "breaks," "broke," "broken," and "breaking" are all forms of the same word. The lemma for all of them is "break."
Linguists and dictionary makers use lemmas to organize words. This is super helpful, especially for languages where words change a lot. The process of finding a word's lemma is called lemmatisation.
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How Words Get Their Main Form
The form of a word chosen as its lemma is usually the simplest one. It's often the form that doesn't have extra endings or changes. But there are some exceptions!
Nouns and Adjectives
For nouns in English, the lemma is usually the singular form. So, you'd look up "mouse," not "mice." If a noun shows who owns something (like "cat's"), the basic form is still "cat."
In many European languages, nouns and adjectives have grammatical gender. For these, the lemma is often the masculine singular form. If the language also has grammatical cases (different endings based on a word's role in a sentence), the lemma is usually the masculine singular form used when the word is the subject of a sentence.
Verbs
For many languages, the lemma for a verb is its infinitive form. This is the "to do" form, like "to go" in English.
English verbs often use their bare infinitive as the lemma. For example, "break" is chosen over "to break," "breaks," "broke," or "breaking." Some verbs, like "must," only have one form. That single form becomes their lemma.
Other languages have different rules:
- In Japanese, the non-past tense (present and future) is used.
- In Arabic, the third-person singular masculine form of the past tense is common.
- In Korean, the ending -da is added to the verb stem.
Some phrases can also have a lemma-like form. For instance, the famous quote from Cato the Elder is often cited as Carthago delenda est ("Carthage must be destroyed"). This is a simplified way of remembering a longer phrase he actually said.
Lemmas in Dictionaries
In a dictionary, the lemma "go" represents all its different forms: "go," "goes," "going," "went," and "gone." This helps you find all related words under one main entry.
Some dictionaries might list "went" and tell you it comes from "go." Others might only list "go." Multilingual dictionaries also have different ways of handling this. For example, a German dictionary might not list ging (the past tense of gehen), but a different one might.
Lemmas are also used in corpus linguistics. This is a field where people study large collections of text. They use lemmas to count how often certain words appear. This helps them understand language patterns.
How Words Sound
A word can sound different depending on the sounds around it. Or it might sound different depending on how much stress it has in a sentence.
For example, the word "some" can be pronounced /sʌm/ when stressed. But it can be pronounced /s(ə)m/ when it's not stressed, like in "some of us." Dictionaries usually give the pronunciation of a word when it's said alone and with stress. They might also note common "weak forms" for words that often sound different when unstressed.
Stem vs. Lemma: What's the Difference?
You might hear the term "stem" when talking about words. A stem is the part of a word that stays the same even when you add endings. A lemma, on the other hand, is the simplest, basic form of the word.
Let's look at "produced."
- The lemma is "produce."
- The stem is "produc-." This is because you can also have words like "production" or "producing."
Sometimes, a word can have several stems but only one lemma. For example, the verb "to go" has two stems: "go" and "went." This is because the past tense "went" actually came from a different old English verb, "to wend"!
Headwords in Dictionaries
A headword is another name for the main word listed in a dictionary or encyclopedia. It's the word you use to find an entry. It also decides where the entry appears alphabetically.
A headword entry can include many things:
- Different meanings of the word.
- Its etymology (where the word came from).
- How to pronounce it.
- Its inflections (all its different forms).
- Phrases that use the headword.
- Even encyclopedic information about the ideas the word represents.
For example, the headword Bread might have these entries:
- Bread
- (noun)
- (verb)
- To coat food in breadcrumbs.
- — to know which side your bread is buttered means to know how to act in your own best interests.
Big dictionaries have many headwords. The Oxford English Dictionary has about 273,000 headwords. The Deutsches Wörterbuch, a large German dictionary, has around 330,000. These numbers can vary depending on how each dictionary counts its entries.
The word "lemma" comes from ancient Greek. It was used to describe the main words in notes written in the margins of old texts. That's why you sometimes see the Greek plural form, lemmata.
See also
In Spanish: Lema (lingüística) para niños
- Lexeme
- Lexical Markup Framework
- Null morpheme
- Principal parts
- Root (linguistics)
- Uninflected word
