第一句：太長了也就是英文中的run-on sentence.不如把第一句變成兩個句子?句子最后有句號
第二句：playing 不是 paying.并且我發(fā)現(xiàn)你在列舉事物的時候沒有標(biāo)點（逗號）.so on 后面有句號.
第三句：each color IS like 不是 Each color just like.elf的復(fù)數(shù)是elves.并且是i think they are LIKE little elves.
第四句：each song THAT contains many stories 結(jié)束.
錯誤太多了.我把你的文章都給改對了.如下：
I am a 14 years old student,the daily learning tasks are heavy,but life after school life is full of joy.It brings me a lot of fun and takes away my sadness.
I have many hobbies,such as playing the piano,drawing,do some sports and so on.I Iike art because I think each color is like expressing different feelings to others.I think they are little elf elves
At first,I do not like playing the piano,but as As I grew older,I found the charm of the music.Behind each song contains a story,I can not help playing the piano but want to understand the implication of its secret.
I m happy when ,I m playing the piano,Feeling very relaxed.I also like listening to pop music,I think they are great,warm and fast songs and feeling the slow songs' tenderness.
I have to cram in extra-curricular,in which I learned a lot of knowledge,but also make friends.
My extra curricular life is full and happy,although a bit busy,but rewarding.
One cannot make an omelet without breaking eggs.
順便說一句.你這文章主題不明確.開頭說跟主題沒有太大關(guān)聯(lián),并且內(nèi)容也不著邊.