He is a nice person

He is a nice person who comes from Japan. He likes my teacher and my friend. He has taught me some simple Japanese words. We have known each other for about half a year, and he's been studying Chinese around a year, and he is already quite good at writing, though his speech needs to improve. Before we talked on QQ and used "Voice" which at first, he felt nervous and wasn't very fluent. Afterwards, however, he was more fluent. Our talks were always very happy, sometimes we laughted together; I liked his laugh, I thought it to be pleasant to hear. He told me he has two children, and a little piquant(调皮的？没有贬义的意思吧？). In his city there is a place called "New Shanghai". He usually went there and says that he liked to go there and buy things.
He helped me a lot,不论是在哪个方面（How to express？怎么表达？）and I thanks so much!



Please help me to correct it,this is my homework.Thanks so much!:)