01、Careless

　　Careless是小心的反义词。如果你careful，那就意味着你做事很用心，想得很多，所以careless意味着做事没有注意或用心。

　　I lost points on the test due to some careless grammar mistakes.

　　由于一些粗心的语法错误，我在考试中丢了分。

　　Don't be so careless with your cell phone; you might break it.

　　不要对你的手机这么粗心;你可能会把它弄坏。

　　02、Carefree

　　This word means “free of worries and responsibilities.”

　　这个词的意思是没有烦恼和责任。

　　If you had a carefree childhood, it means you enjoyed yourself because you didn't have much stress or worry in your life. A carefree vacation would be a trip on which you stop thinking about work and other obligations.

　　如果你有一个carefree(无忧无虑的)童年，这意味着你生活中没有太多的压力或担心而且非常享受。一个carefree(无忧无虑的)假期就是你停止思考工作和其他义务的一段旅程。

　　You can also describe a person as carefree or as having a carefree attitude, meaning that their personality is the type that doesn't worry a lot.

　　你可以描述一个人是carefree，或者有carefree的态度，意思是他们是那种不怎么爱担心的人。

　　总结

　　Being careless is negative, it means not giving the necessary attention or thought to your wordsactions. And being carefree is positive; it means feeling nice and light, without stress, worries, or heavy obligations.

　　Careless是消极的，它意味着你没有对你的言行给予必要的关注或思考。而carefree是积极的;它意味着感觉很良好和轻松，没有压力，担心，或沉重的义务。