If two different things coexist, they are both there at the same time, or in the same place.

If two different things如果兩個不同的東西 coexist coexist（共存） they are both there它們都同時存在 at the same time在同一個時間 or in the same place或同一個地方

Two ideas can coexist in one person's mind. Two groups can coexist in one city. Two kinds of animal can coexist in one forest.

Two ideas兩個想法 can coexist可以共存 in one person's mind在一個人的腦子裡 Two groups兩個群體 can coexist可以共存 in one city在同一座城市裡 Two kinds of animal兩種動物 can coexist可以共存 in one forest在同一片森林裡

The word does not, by itself, say that they like each other — only that they are both present.

The word這個字 does not, by itself, say本身並沒有說 that they like each other它們喜歡彼此 only that they are both present只是說它們都存在

Though actually, people often hope for a softer meaning: they say coexist when they mean "live side by side without fighting." You will hear "learn to coexist" in talk about neighbours, religions, or political camps. In science it can be quite dry: two chemicals coexist in a mixture; no friendship is implied.

Though actually不過事實上 people often hope for a softer meaning大家常常希望它帶點更柔和的意思 they say coexist他們說coexist的時候 when they mean其實想表達的是 "live side by side without fighting"「和平共處、不打架」 You will hear你會聽到 "learn to coexist"「學習共存」 in talk about用在談 neighbours鄰居 religions宗教 or political camps或政治陣營的時候 In science在科學裡 it can be quite dry可以很乾巴巴的 two chemicals兩種化學物質 coexist in a mixture在混合物裡共存 no friendship is implied不帶任何「感情」的意思

It is a bit formal, but not rare. Students meet it in textbooks and news.

It is a bit formal這個字有點正式 but not rare但不算少見 Students學生 meet it會遇到它 in textbooks and news在課本和新聞裡