Use the word "less" when talking about an amount that is small or smaller when compared to another amount.
When this word Is an adjective, it’s used before noncount nouns:
I have less free time now than I had last year.
In the winter, many people get less exercise because they stay indoors more often.
If you eat less meat and more vegetables and fruit, you might feel healthier.
Is it possible for you to use less energy?
Budget cuts usually result in less spending. (Use "less" with gerunds.)
He’s been getting less sleep lately.
When "less" is an adverb, it modifies a verb or an adjective:
Bananas cost less if you buy them at the other store.
Joe sees his girlfriend less after she moved away to go to college.
They’re less certain of their future after their house burned down.
Bob was not chosen for the job because he was less qualified than the other applicants.
I worried less when I was younger. Now I worry more about everything.
The word "less" can also be used as a noun:
We can get by on less.
The less you say about this the better.
Less is known about the virus than authorities would have us believe.
They have less and less to do now that they are retired.
If you add "en" to "less," you can form the verb "lessen," which means to make less or reduce. (Don’t confuse this with the word "lesson.")
Walking to work instead of driving to work can help lessen your stress.
Taking an aspirin might lessen the pain you are experiencing.
Governments around the world are trying to lessen the impact that the corona virus might have on their economies.
There are some popular expressions that include the word "less."
You can do more with less.
Less is more. (This expression is applied when talking about a minimalist approach to something.)
I couldn’t care less. / I could care less. (I don’t care.)
Less talk, more rock. (Action is much better and more productive than talking.)
We chose the lesser of two evils. (GIven two bad choices, we chose the one that was better than the other.)
He took the road less traveled. (This is a reference to Robert Frost’s poem, The Road Less Traveled, in which a person must make an important decision. This decision, according to many interpretations, leads to a greater challenge; therefore, the decision is more worthy of admiration.)