as for me, it is ideal if i could found someone that talk like a friend, but correct me like a teacher... hehe.. ^•^

老师、朋友都可以。可是做朋友是最重要的，因为如果他们兴趣的、性质不一样，怎么一起聊天啊？

  a friendly teacher,  

 a friend don't correct  mistakes in what I said.

Like everyone can choose anyone who are favourable to self as friends. The language partner you want to choose could vary. The most important thing you have to know is your destination you had better define at first.

亦师亦友，相互帮助学习。子曰：三人行必有我师。这里高手如云，定能受益匪浅。