谁能帮帮我看一下这篇文章~~帮我改一下语法~~~怎么乱七八糟的写的

谁能帮帮我看一下这篇文章~~帮我改一下语法~~~怎么乱七八糟的写的
Once,I worked as a 7-year-old child’s piano tutor. That time, I was 14-year-old and just received the grade 8 certificate of The Musicians’ Association of Jiangsu Province (belongs to Certificate of Art Grade Examination of China).
In fact, the boy had a piano teacher. May be because of his age, he needs a person to help him understand the lesson and teach him how to practice the song or fingering. I was happy that I can accompany with him, cause for me, help him or even to be his teacher was very remarkable, it gives me a great satisfaction and a sense of accomplishment. Although the time is only 2 months, it still added a vital life experience to my life.