Is less water correct since u guys said the use of less is for single items?

Is 'less water' correct, as you guys said the use of 'less' is for single items?

YES

Degree determinative "less" is used with non-count singulars like "water":

There is less water in the pond than last year.
Kim has less money than Pat

It can also be used with plural count nouns as an alternate to "fewer":

I've fewer/less shirts than Ed.
He made fewer/less mistakes than the others.

PaulM

Paul Matthews: ""less" is used with non-count singulars (and with) plural count nouns.

I don't know what language YOU speak, but not in English.

less water/sugar/salt
fewer people/cars

Are you AMERICAN?

No, I'm English, and a native speaker of BrE.

"Less" is perfectly acceptable as an alternate to "fewer"; indeed in many cases it's actually preferable. Only the likes of prescriptivists insist on "fewer" for all things countable.

For example, "days" is a count noun, yet "Your package will arrive in seven days or less" is far better than "?Your package will arrive in seven days or fewer"; but the prescriptivists and subeditors seem deaf to such matters.

Also, at the fast checkouts in supermarkets, you will see "Ten items or less". "Items" is a count noun, but "fewer" would be ridiculous there.

Here's another example: "Quite often, these games don't even turn out to be good: Fewer than half of them have been decided by 10 points or fewer."

That "10 points or fewer" phrase on the end is a desperate and quite ridiculous effort at obeying the prescriptive rule that you should use "fewer" for all things that can be counted, and "less" only for mass quantities. There is nothing wrong with "10 points or less" in this context.

See what I mean?

PaulM

Paul,

I like how you explain things. It's clear to me. You're good.

I adhere to the opinion expressed by Oxford Dictionary:

" In standard English, 'less' should only be used with uncountable things ( less money, less time). With countable things, it is incorrect to use 'less' ( 'less people' and 'less words'); strictly speaking, correct use is 'fewer people' and 'fewer words'.

Descriptive grammar fails to take into account whether the expression comes before the noun, or after.

more than 10 items
fewer than 10 items

10 items, more or less
10 items or less

My two sisters and John are definitely coming to the party.
compare
There is/There's John and my two sisters who are definitely coming, with Paul as a 'maybe'.

Judging by the examples of descriptive grammar I see every day, then "There is people in this world who…" would be "quite acceptable" to you.