you are not a kid any longer. you should try your best to ....

You are not a child (any ) (longer ).You should (try )( to)take care of yourself. " 你已不再是小孩子了，你应尽力照顾自己。" 这里不能用no longer,因为原文中已经有not了， no longer=not an...y longer no more=not any more 如果要用no longer来表示，则为：You are no longer a child. 另外要说明的是，any longer和any more是不一样的， any more用于短暂性动词 any longer用于延续性动词；另外他们侧重的方面不同。前者侧重时间，比如： He no longer lives here. = He doesn't live here any longer. 他不在这儿居住了。(一个时间以前他住在这儿，过了这个时间，他就离开了。) 后者侧重程度和数量，比如： You can drink no more. = You can't drink any more. 你不能再喝了。(喝酒的量到了一定程度，不能再继续下去了。) 【公益慈善翻译团】真诚为您解答！

You are not a child (any longer或any more ) , you should (try to ) take care of yourself .

You are no longer a child so you have to try your best to take care of yourself.