We use 'less' to show a smaller amount of something. It is often used for things we cannot count easily.
I have less water today.
She has less money now.
'Less' can show that something happens or is done to a smaller degree. It compares actions or qualities.
He studies less than before.
I like this less now.
In some formal or old usage, 'less' is used to mean 'except' or 'not including' someone or something.
Everyone came less John.
I want all less the last one.
'-less' is a common ending added to nouns to create adjectives that mean 'without' that thing. For example, 'fearless' means without fear.
The word 'hopeless' means without hope.
'Careless' means not careful.
'Less' can be used as a noun, talking about a smaller quantity or amount of something.
Use less of the sugar please.
Can I have less of that.
In idioms, 'less than' + adjective means 'not really' or 'not fully' like being not honest or not important.
His apology was less than sincere.
That excuse is less than honest.
'Less' is used in math when you subtract one number from another. It means the smaller amount after removing a number.
Five less three is two.
Ten less four equals six.
