词性不同。
care是动词或者名词,careful是形容词,carefully 是副词。详解: care 英[keə(r)] 美[ker]v. 照顾; 关心; 担心; 喜爱;n. 照顾; 小心; 忧虑;[例句]Does anybody know we"re here, does anybody care? 有谁知道我们在这儿?有谁在乎?careful 英[ˈkeəfl] 美[ˈkerfl]adj. 仔细的,小心的; 周到的; 慎; 心细;[例句]Be very careful with this stuff, it can be dangerous if it isn"t handled properly 这东西一定要小心,稍不注意的话就会有危险。carefully 英["keəfəlɪ] 美[ˈkɛrfəlɪ]adv. 仔细地; 小心谨慎地; 警惕地; 周密地; [例句]We carefully watched every detail of his action. 我们仔细观察了他动作的每个细节。