What is vocabulary?

Words, expressions, and meanings

Vocabulary is the collection of words and expressions used by a person, a group, or a subject. Your personal vocabulary includes language you understand and language you can use. A science vocabulary, for example, includes terms that help people describe scientific ideas.

A vocabulary entry usually connects a written form with a meaning. Learning the sound, spelling, and grammatical role makes that connection more useful. Expressions such as on the other hand also matter because their meaning and function depend on the whole phrase.

Knowing a word has several parts

You may recognise a word on a page without being ready to say it in a conversation. You might know one meaning but not another. Consider light: a light bag and a light in the hallway use the same spelling in different ways.

An entry's part of speech helps identify its role. A noun can name something; a verb can express an action or state. A complete sentence shows more than a label alone, so read the example as well as the definition.

• Meaning: what does it express here?
• Form: how is it spelled and changed?
• Use: where does it fit naturally?

Vocabulary changes with the situation

The words you use with a friend may differ from those in a laboratory report. Some language is conversational, some formal, and some specific to a field. A more formal word is not automatically a better choice.

Use the audience and purpose to guide you. Help may be clearer than assistance in a quick message. In another setting, assistance may fit the expected tone. Precision and clarity matter more than making every sentence sound difficult.

Build depth as well as breadth

Breadth concerns how many words you know; depth concerns how well you know them. More words can widen the texts you approach, while closer attention to familiar words can improve how you understand and use them.

Try investigating a familiar word: find another meaning, a related form, and a common word partnership. Then compare two example sentences. This turns an entry into usable knowledge rather than another item in a count.