To lessen is to become smaller, or to make something smaller — not only in size, but in strength, importance, pain, or value.

To lessenlessen，is to become smaller, or to make something smaller就是變小，或是讓某樣東西變小——not only in size不只是體積上，but in strength, importance, pain, or value也可以是力道、重要性、痛楚，或價值上。

Pain can lessen after medicine. A problem can lessen if people fix part of it. A government may try to lessen the cost of food.

Pain can lessen after medicine疼痛在吃藥之後可以lessen（減輕）。A problem can lessen一個問題可以lessen（減輕），if people fix part of it如果人們解決了它的一部分。A government may try to lessen the cost of food政府可能會試著lessen（降低）食物的成本。

It is a slightly formal verb, but not rare; in speech people also say reduce, ease, die down, or get less. It is simply less plus -en, an old ending that turns an adjective into a verb, the same kind of ending as in shorten, darken, and widen.

It is a slightly formal verb, but not rare這是個稍微正式、但不算少見的動詞；in speech people also say reduce, ease, die down, or get less在口語裡人們也會說reduce、ease、die down，或get less。It is simply less plus -en它就是less加上-en，an old ending that turns an adjective into a verb一個把形容詞變成動詞的古老字尾——the same kind of ending as in shorten, darken, and widen跟shorten、darken、widen裡的字尾是同一種。

It has nothing to do with a lesson in class, though the two words sound almost the same, and that is the trap.

It has nothing to do with a lesson in class它跟課堂上的a lesson（一堂課）一點關係也沒有，though the two words sound almost the same儘管這兩個字聽起來幾乎一樣，and that is the trap而那正是容易搞混的地方。