Hi, I think the Pinyin part is correct, but I got confused with the Chines part.
Do you mean, "I taught Piotr yesterday. He is a Russian and I completed my English lessons with him"?
If it is, the Chinese translation will be "我昨天教Piotr了,他是俄國人而且我教完他我的英文課程了"
For your reference :)