A noun names something — a person, place, thing or idea. A verb expresses an action or a state of being. The complication in English is that a great many words are both: "run" is a verb in "I run" and a noun in "a run". Position in the sentence, not the word itself, usually decides.
The core difference
The two most basic parts of speech, and the ones that overlap most in English.
- noun — names: dog, London, freedom, a run.
- verb — acts or states: run, seem, is.
How to tell which one you are looking at
Test the slot, not the word. If it follows the or a, or can be made plural, it is behaving as a noun. If it changes for tense — ran, running — it is behaving as a verb. "I run" and "a run" contain the same letters doing entirely different jobs.
Conversion
English turns nouns into verbs freely: to google, to text, to host. This is called conversion or zero-derivation, and it is one of the language's most productive habits — which is why the noun/verb boundary is fluid rather than fixed.
Frequently asked questions
Can a word be both a noun and a verb?
Yes, and thousands are — run, walk, hope, text. Position in the sentence decides which job it is doing.
How do I identify a noun?
See whether it can follow "the" or "a", take a plural, or be replaced by a pronoun. Those tests are more reliable than asking what the word means.
What is conversion in grammar?
Using a word from one part of speech as another without changing its form — turning the noun google into the verb to google.