語法錯誤主要有以下幾點：
1.Nature just likes an old man,it can tell you something about life and what you are doing.
應該為：Nature is just like an old man,which can tell you something about life and what you are doing.
你原句中的like用作動詞,有第三人稱單數(shù).但like用作動詞時意思為“喜歡”.但明顯你所要表達的意思是“像”,但like只有作為介詞的時候才有“像”的意思.因此要把like改為介詞形式的,前面加be.
然后it要改為which.因為你前面用的是逗號,一個句子沒完的.所以后面應改為一個從句吧,用which引導.
2.I like listening the songs of birds,and I like smiling to each flower
listening后面要加to.listen to sth
3.People when see that,always laugh.
應改為when people see that,they always laugh
或改為：when seeing that,they always laugh 也可以
4.I JUST WANT TO BE WHICH I WANNA BE.
which 改為 what
be 后面的不是定從是表語從句,不應該用which 引導的.what引導表語從句.
LZ寫得不錯的～只是有點語法錯誤.加油!