Fewer vs. Less and Then vs. Than: Rules and Examples
Overview
Some of the most persistent errors in English involve words that look or sound nearly identical but follow different rules. Fewer and less are both used to describe smaller quantities, yet they cannot be used interchangeably. Then and than differ by a single letter, yet each belongs to a completely different grammatical category. Mixing up either pair produces sentences that a careful reader will notice immediately.
These are not obscure rules limited to formal writing. Fewer versus less appears in everyday conversation, product labels, and news articles. Then versus than surfaces in comparisons, which are among the most common structures in English at every level.
Fewer vs. Less
The core distinction between fewer and less depends on whether the noun being modified is countable or uncountable.
Fewer is used with countable nouns: nouns that can be made plural and counted individually. Less is used with uncountable nouns: nouns that refer to substances, qualities, or concepts that cannot be counted as separate units.
When the Noun Is Implied
Sometimes the noun is not stated directly but is implied by context. The same rule still applies based on what the implied noun is.
Fewer vs. Less with Numbers and Measurements
When a number precedes a unit of measurement, less is typically used, even though the unit might appear countable. The phrase refers to an amount or quantity as a whole rather than to individual units.
This applies consistently with distances, weights, times, sums of money, and percentages when used as measurements.
The Informal Use of Less
In informal speech and some commercial contexts, less is frequently used with countable nouns. Signs that say "10 items or less" are common in shops. This usage is widely accepted in informal registers, but in formal and academic writing, fewer with countable nouns remains the standard.
Then vs. Than
Then and than are pronounced similarly in fast speech, which is one reason they are so frequently confused in writing. They belong to entirely different word classes and serve completely different functions.
Than is a conjunction and a preposition used in comparisons. It appears whenever two things are being measured against each other.
Then is an adverb used to refer to a point in time, to indicate what happens next in a sequence, or to express a logical consequence.
Using Than in Comparisons
Than appears after comparative adjectives, comparative adverbs, and certain expressions of difference.
Using Then for Time and Sequence
Then functions as a time adverb. It can refer to a specific point in the past or future, describe the next step in a sequence, or introduce a logical consequence following a condition.
Fewer and Less Compared
| Situation | Use Fewer | Use Less |
|---|---|---|
| Countable nouns | fewer students, fewer errors | |
| Uncountable nouns | less water, less time | |
| Measurements and amounts | less than five kilometres | |
| Implied countable noun | fewer than expected | |
| Informal speech (non-standard) | less items (informal only) |
Then and Than Compared
| Word | Word Class | Function | Example |
|---|---|---|---|
| than | conjunction / preposition | comparison | faster than before |
| then | adverb | time, sequence, consequence | mix well, then bake |
Common Mistakes to Avoid
Mistake 1: Using Less with Countable Nouns in Formal Writing
In formal and academic contexts, fewer is required with countable nouns.
Mistake 2: Using Fewer with Uncountable Nouns
Fewer only works with nouns that can be counted individually.
Mistake 3: Writing Than When Then Is Needed
A sentence that describes a sequence of events requires then, not than.
Mistake 4: Writing Then When Than Is Needed
A sentence comparing two things requires than, not then.
Mistake 5: Confusing Then and Than After Comparatives
Comparative adjectives and adverbs are always followed by than, not then. If the sentence contains a word like more, better, faster, higher, or fewer, it almost certainly needs than immediately after.
Mistake 6: Applying the Measurement Exception Too Broadly
The rule allowing less with numbers applies only when those numbers represent measurements or amounts treated as a single quantity. It does not apply to straightforward counts of individual items.
Practice Exercises
Exercise 1: Fewer or Less
Choose the correct word to complete each sentence.
- The revised edition contains _______ errors than the original.
- She drinks _______ coffee in the afternoon.
- _______ than half the group completed the survey.
- The journey takes _______ than three hours by train.
- There are _______ opportunities in smaller markets.
Exercise 2: Then or Than
Choose the correct word to complete each sentence.
- The second version of the document was clearer _______ the first.
- Add the vegetables, _______ reduce the heat.
- He was younger _______ most of his colleagues.
- We met in the old office back _______.
- If the application is approved, _______ the contract will be issued.
Exercise 3: Identify and Correct the Error
Each sentence contains one error. Rewrite the sentence correctly.
- There were less volunteers than the coordinator had hoped.
- The final report was longer then the draft.
- She ran faster then anyone else in the group.
- Mix the ingredients together, than pour the batter into the pan.
- The region records fewer rainfall than the coastal areas.
Summary
| Pair | Rule | Correct Example |
|---|---|---|
| fewer | Use with countable nouns | fewer students, fewer mistakes |
| less | Use with uncountable nouns | less water, less time |
| less | Use with measurements and amounts | less than two hours |
| than | Use in comparisons, after comparatives | better than expected |
| then | Use for time, sequence, and consequence | mix well, then bake |
The countable and uncountable distinction governs fewer and less. The difference between comparison and time governs than and then. Keeping those two principles in mind resolves the vast majority of errors that arise with these four words.