Phil A great question – we've got 'agree' and four different prepositions. All of these are about agreement, but changing the preposition changes the kind of object the verb has, and this can be complicated. So, let's look at each phrase in turn, starting with 'agree with'. Now, we often use this with people, don't we?
Jiaying Yes, we do. 我们都知道动词 “agree” 的意思是 “同意，赞同”。如果我们改变它后面接的介词，那么将会相应地改变动词后的宾语类型。
先来看 “agree with”。“Agree with someone” 的意思是 “赞同、同意某人的意见或观点”，而 “agree with something” 则表示 “赞同一个想法、一项政策或规定”。听三个例句。
Examples I don't agree with him – he is so wrong about that! （我不同意他的观点。他在那件事情上大错特错！）
You say that English is one of the most important languages to learn, and I agree with that! （你说英语是最值得学习的语言之一，我同意这个观点！）
I definitely agree with the university's plagiarism policy. （我完全同意大学的有关剽窃的规定。）
Phil OK, so you can agree with a person or an idea. If we use 'agree about', it means you think the same as someone else in relation to a particular topic.
Jiaying 是的，搭配 “agree with” 和 “agree about” 之间的区别其实很微妙。刚刚我们说到，如果你 “agree with someone” 或者 “agree with an idea”，意思就是你 “同意某人的观点或某个想法”；而如果你和另一个人 “agree about something” 或者你 “agree with someone about something”，意思则是你和这个人 “对某件事情所见略同”。听两个例句。
Examples We were talking about the best ways to save money, and we agree about everything! （我们当时在讨论省钱的最佳方法，结果我们的意见完全统一！）
We'd never met before, but we agree about the best films, we agree about the best music. Basically, we agree about everything! （我们之前素未谋面，但我们对什么是最好的电影和音乐的看法都完全一致。我俩基本在所有事情上的看法都相同！）
Phil So, 'agree with' and 'agree about' are to do with people and ideas. Now, let's look at 'agree on' – this is often about a decision. When a decision is agreed, you can say that everyone 'agrees on' what to do next.
Jiaying 通常情况下，搭配 “agree on” 的意思是 “（双方或多方）对某个决定达成共识，商定某事”，后面接名词。比如：“agree on a plan（就计划达成一致）”、“agree on a deal（达成一项协议）”。听下面的三个例句。
Examples They talked all night, but they finally agreed on a deal that suited everyone. （他们谈了一整夜，最后终于达成了一个所有人都满意的协议。）
The future looks difficult, but they agreed on a plan to make it work. （虽然未来很难，但他们达成了一个使之可行的计划。）
We agreed on a new schedule that everyone accepted. （我们商定了一个大家都接受的新时间安排。）
Phil Related to that is 'agree to' – we use that with a suggestion. If you agree to a suggestion, you accept it and will do what was suggested.
