Ⅰ. talk with 后接的对象作宾语，介词with可用to代替。如：
① He was talking with / to a friend. 他在与一位朋友谈话。
Ⅱ. talk about “谈论”，后接谈话的内容，宾语可以是人，也可以是物。如：
① What are you talking about ?你们在谈论什么?
② Let’s not talk about it now. 咱们别谈这事了。
Ⅲ. talk of “谈到、谈及”，与talk about 同义，只是talk of 仅指“浅谈表面现象(如作者、书名等)”如：
① We often talk of you. 我们常谈到你。
Ⅳ. talk on “论述”不仅指内容，而且还指评论。如：
① They seldom talk on politics in those days. 那时候他们很少谈论政治。