- As a noun, fun means enjoyment.
- Fun is not universally accepted as an adjective. People who do accept it as an adjective seem to prefer more fun and most fun over funner and funnest.
Whether fun or more fun is correct seems like a simple question, but the answer isn’t exactly straightforward. To understand, you must examine the background of the word fun. Let’s get started.
Fun, the Noun
Fun is enjoyment, or something that provides amusement. If you have fun in a greater quantity, you have more fun. Some people say that fun can function only as a noun. Before we address that issue, let’s look at some examples of fun as a noun.
Fun, the Adjective
As early as the 1900s, people were using fun as an adjective in speech and informal writing. People use it to describe things or people relating to fun. Sometimes, it describes things that are whimsical. Many people, perhaps most people, strongly prefer more fun and most fun as the comparative and superlative forms of fun. Still, plenty of others label things funner and funnest. Many dictionaries acknowledge this use, but still label the adjective form as informal. Here are some examples of fun used as an adjective.
If you’re not sure which way to go, remember that more fun and most fun will raise fewer eyebrows than funner and funnest.
If you think fun belongs only in the noun category, then “more fun” is the only choice for you. Do you accept fun as an adjective? If you do, you can also embrace funner and funnest in informal writing. If enough people do so, it will probably become accepted as standard before long. Speaking of fun, why not learn whether you are using some other English expressions correctly?
from Grammarly Blog https://www.grammarly.com/blog/funner-vs-more-fun/