less/fewer than

[Winwin2011]

1.There were less than 10 people at the meeting.
2. There were fewer than 10 people at the meeting

3. There will be fewer trees in the future
4. There will be less trees in the future

Which sentence is more natural in verbal English?

[5jj]

In informal spoken English, you will hear all of them. The purist would prefer 'fewer' in both, especially in sentences #3/4.

[emka]

My pet hate!
I am not a stickler when it comes to spoken language, but if it's written, no matter what language, that's a different cup of tea, and I regularly feel my cortisol levels rise when I see what sometimes makes it into print.
This happened every time I stood in line at the express check-out with the sign "Less than ten items" above it - and I counted, how many items people put on the conveyor belt. (Often more than ten, but that's not why I got upset).

[5jj]

My pet hate! [...]
This happened every time I stood in line at the express check-out with the sign "Less than ten items" above it - and I counted, how many items people put on the conveyor belt. (Often more than ten, but that's not why I got upset).

I don't like it, either, but it can be justified.

£10 is a lot of money. This is correct; 'are' is wrong. We see £10 as a sum of money.
10 items is not a lot. This is possible. We see 10 items as a purchase.
Less than 10 items. People who have made a {purchase of 1-9 items} can queue here.

That is why I implied in my first response that the OP's #1 was less unnatural (!) than #4.

[emka]

Maybe. It could be people’s concepts of things (sum, purchase).
My – completely unsubstantiated – guess, purely gut feeling, is that “less” requires less (!) effort to pronounce because it is only one syllable and people tend to economise even on syllables (cf. common abbreviations such as mod cons, invite, fridge). “Less” seems also more common than “fewer” because it is used in comparatives (more friendly/less friendly).
Just a hypothesis…

But of course I digress from Winwin2011’s question. I got carried away and should stick to the minimalist concept of Less is More.

[Winwin2011]

When I was a student, the English teachers told us to use 'less(than)' with uncountable nouns, while 'fewer' to be used with countable nouns. However, I've seen many people use 'less' instead of 'fewer" with countable nouns.

[5jj]

When I was a student, the English teachers told us to use 'less(than)' with uncountable nouns, while 'fewer' to be used with countable nouns. However, I've seen many people use 'less' instead of 'fewer" with countable nouns.

This is so common nowadays, that I rather think that we 'fewer' users have lost the battle. I don't think it will be long before we stop teaching the difference.

At the moment, I still teach the difference, but I always tell my students that many native speakers do not follow the rule.

[emsr2d2]

I agree with all other comments. Once upon a time, I'm sure there was a rule that we were taught at school and most people followed but, as with so many other things, it's not the case any more. I think it's probably true that because "less" is used so much more frequently in other constructions, it is just becoming the norm.

Last night, my flatmate and I were watching a game show. The contestant had asked to improve his chances on a particular round by using his "simplify" choice. In the game he had to memorise a pattern of squares which were illuminated in front of him for 3 seconds. I asked my flatmate what he thought the simplification would consist of. At the same time that he answered my question, I said what I thought would happen.

He said "Less squares."
I said "Fewer squares."