A person who works hard makes an effort. The word "effort" is a noun. We use this word when someone tries to be successful at something.
Her work shows a lot of effort.
Tommy made an effort to do well on his assignment.
There was a big effort to save the building from demolition.
Efforts have been made to improve the air quality in our city. (This sentence is in the passive voice.)
My students’ efforts to improve their English eventually pay off.
He always makes an effort to finish his work on time.
Add "less" to make the adjective "effortless." You can use this word to describe something that is easy or looks easy. It’s also used when someone doesn’t try very hard.
The audience did not appreciate the effortless performance. One of the actors even forgot some of his lines.
Her piano playing looks effortless, but she spends a lot of time practicing.
Learning a new language is not an effortless activity. It requires hard work.
John completed all of his work effortlessly. (This sentence uses "effortlessly" as an adverb.)