Fewer is the comparative of few (used with countable, plural nouns).
Less is the comparative of little (mostly used before uncountable, singular nouns).
- A receptionist would make less money than a director.
- We used to go to the seaside every weekend, but now we have less time.
- There were fewer eggs in the fridge than we had hoped.
- I have fewer books than my grandfather.
Less may also be used before plural nouns in an informal style, although this is not typical:
- These days I’ve got less/fewer problems than I used to have.
Less and fewer are used with the preposition OF before determiners (such as the, my, this) and pronouns.
- I wish my wife spent less of her money on expensive clothes.
- There are fewer of us at the college reunions each year.
- Fewer of the interviewees were wearing ties than we’d expected.
- Do you still drink a lot of alcohol? – No, I drink less of it nowadays.
Of is not used before nouns without determiners.
- If you want to lose weight, you should eat less chocolate and bread.
- Fewer people have strictly healthy diets these days.
- Peter has fewer friends than his brother.
- I don’t think less time would’ve made him change his mind about leaving.
Less and fewer can stand on their own, that is without a noun, if the meaning is clear or as indefinite pronouns.
- People do still go to church, but fewer/less than 50 years ago.
- If you work less, you will earn less.
- Have you got at least a kilo of apples? – No, we’ve got fewer/less.
- Unfortunately, I sleep less than I should.
On the flip side….
More is the opposite of ‘fewer’ and ‘less’ and can be used in quite a few different ways.
The comparative form: more is usually used with adjectives that have more than one syllable (except for adjectives ending in -y) to express that there is more of a particular quality.
- My sister is more talented than me.
- Her outfit was more extravagant than what the hostess was wearing!
The determiner (more+noun): when more is used before a noun it acts as a determiner to state that there is more of something. Generally, the preposition ‘of’ is not used in this structure.
- She has more children than any of her friends.
- I always have more homework to do than my siblings.
The lonely one: more can be used on its own if the context that it is being used in has already been established and is clear to the listener.
- Can I have some more please? (A child asking his mother for more of what is already in his cup)
- I would like to have more but I think it’s too soon right now. (A couple talking about having more children)
The one with numbers (number+more+noun+infinitive): A number followed by more and used with a noun and an infinitive defines the quantity of a task that remains to be completed. Please note that in this structure, ‘more’ can sometimes be replaced by ‘another’.
- I have to write two more articles before Wednesday next week.
- I would like to place just one more bet!
- Could I have one more/another glass of juice please?
The one with OF (more of+determiner+noun): ‘More of’ is usually used with articles and other determiners when talking about something in particular, which can be about people or objects.
- He’s more of a ‘mummy’s boy’ than I thought!
- This computer seems to be more of a problem than a solution!
- I’ll have more of the delicious red wine you gave me yesterday please.
The adverb: more can be used as an adverb to describe an increase in an action or feeling.
- She looks more beautiful every day.
- This house feels more suffocating every time I step inside.
- I like her more every/each time I see her.
The double-more: the comparative phrase ‘more and more’ before an adjective is used to state that someone or something is increasingly becoming a certain way. In other words, if you’re trying to say there is a growing tendency towards something, then use the phrase ‘more and more’.
- I feel more and more comfortable in this neighbourhood every time we meet new friendly people.
- She’s getting more and more nervous as her wedding day approaches.
- It is becoming more and more difficult to live without a smartphone.