'Vocabulary' or 'Vocabularies'? Which One Is Correct? | Mastering Grammar

(Last Updated: 11 August 2026)

Vocabulary or Vocabularies: Which One Is Correct?

When referring to the set of words and expressions known to, or used by, a person or group in a particular language, dialect, or field of study, we use the singular form vocabulary, not vocabularies:

✅ The English language has a vast vocabulary. (= There are many words in the English language.)
❌ The English language has vast vocabularies.

✅ Reading regularly will greatly expand your vocabulary. (= Reading regularly will greatly increase the number of words you know.)
❌ Reading regularly will greatly expand your vocabularies.

✅ John has an impressive vocabulary because of his love for reading. (= John knows a large number of words because he loves reading.)
❌ John has impressive vocabularies because of his love for reading.

✅ The correct use of legal vocabulary is one of the most important skills that a lawyer can have. (= Knowing how to use legal terms correctly is crucial for a lawyer.)
❌ The correct use of legal vocabularies is one of the most important skills that a lawyer can have.

We use the plural form vocabularies only when referring to two or more languages, dialects, or fields of study:

✅ The linguist's research focuses on the vocabularies of indigenous languages in Africa.

✅ Art and music have similar vocabularies since they both relate to aesthetics.

✅ Chris is an expert in both legal and medical vocabularies as he is a qualified lawyer and medical doctor.

✅ The vocabularies of scientists and musicians are vastly different.

Source: Oxford Advanced Learner's Dictionary

It is important to note that when referring to an individual word, it is incorrect to call it a vocabulary. An individual word is simply called a word:

✅ My favourite English word is 'serendipity'.
❌ My favourite English vocabulary is 'serendipity'.

✅ In today's lesson, you will learn ten new words related to the environment.
❌ In today's lesson, you will learn ten new vocabularies related to the environment.

✅ By fifteen months of age, the boy knew around 500 words.
✅ By fifteen months of age, the boy had a vocabulary of around 500 words.
❌ By fifteen months of age, the boy knew around 500 vocabularies.

Lastly, it is worth noting that the shortened form vocab is often mispronounced with emphasis on the second syllable rather than the first. The correct pronunciation is VOH-kab (/ˈvəʊkæb/), with the stress on the first syllable. Avoid saying va-KAB.

Source: Cambridge Dictionary

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Examples from the Media

Storytelling boosts vocabulary, memory and self-esteem. —Toronto Star (2013)

The Oxford English Dictionary lists some 500,000 entries. By contrast, the German vocabulary has only 185,000 words; French, a paltry 100,000. —The Washington Post (1993)

In the past it had been thought children who spoke two languages could have been at a disadvantage because the presence of two vocabularies would lead to delayed language development. —Daily Mail (2015)

The vast majority of Australians, then and now, tend to speak a version of general Australian English with only minor regional variations—not enough to amount to dialects, the regionally distinct forms complete with vocabularies of their own, as spoken in different parts of Britain and the United States. —The Sydney Morning Herald (2021)

Real-World Examples of Misuse

Saying over 600 vocabulary is not only unidiomatic but also illogical. A vocabulary is a collection of words rather than a single word. Therefore, 600 vocabulary should be corrected to 600 words. Alternatively, you can say 600 vocabulary words or 600 vocabulary items, both of which are commonly used in language teaching. Vocabulary words specifically refer to individual words that you aim to memorise to enhance your vocabulary, while vocabulary items encompass both words and phrases.
(Source: CLASSROOM Primary Good Writing Guide, Book 3)
(Also from the Same Series: 1)

1. The heading Instructions may be considered redundant, as a reader would know that what follows is a set of directions without being told.
2. The verb check implies verifying that something is correct. In this assignment, however, students are not verifying—they are discovering. They need to use a dictionary to find the meanings and write them in the given table. A suitable phrasal verb for this task is look up, which means 'to search for and find information in a reference book'.
3. Removing the second definite article creates a smoother, more concise parallel structure, with both meanings and Chinese translations preceded by the same the.
4. Vocabularies is not the correct term for a list of discrete lexical items. In the context of a glossary worksheet, each entry is a word (or alternatively, a vocabulary item).
(Source: HKUGA College)

(Source: 斯勤教育中心)

1. While there is nothing wrong with using can, the phrase be able to in the second part of the sentence makes it redundant because can and able have similar meanings. It would be better to use will instead of can, which not only eliminates the redundancy but also adds a sense of certainty and promise to the statement.
2. It is incorrect to say 100 vocabularies. Instead, you can say 100 vocabulary words or simply 100 words to indicate that students will learn 100 new words. The term vocabulary word is commonly used in language teaching to refer to a word that students are expected to learn the meaning and usage of.
3. The wording 150 words or more is a more natural and common expression used to convey the same idea.
(Source: 現代小學士)
(Also by the Same Centre: 1)

1. The phrase as a clue is more concise and natural-sounding than the original, as clue is a standard term in testing contexts that immediately conveys the purpose of the letter as a helpful hint.
2. You cannot say each vocabulary because vocabulary refers to the entire set of words rather than a single word. The instruction should refer to each item on the vocabulary list as each word, each vocabulary word, or each vocabulary item.
(Source: Diocesan Boys' School)

1. Comprehension refers to the abstract skill or process of understanding, not to the physical text. You cannot decode an abstract ability; you can only build, improve, or demonstrate it. If you mean that the student is able to decode a specific reading passage, you should write decode the text.
2. Vocabulary refers to a whole set or collection of words. You cannot use it with the indefinite article a to mean a single word. In this labelling activity, the learner is identifying one specific word per picture, so the correct term should be word.
3. Since the worksheet contains multiple labelling items, the instruction should apply universally. Using each picture clearly signals that the learner must do this for every picture on the page, rather than just one.
(Source: Hennessy Road Government Primary School (Causeway Bay))
(Also by the Same School: 1/2)