agree with...

表示同意某人或某人的意见、观点、决定、想法、安排、解释

• I don't agree with you.
• They agreed with this idea. 他们同意这个想法。
• I don't agree with what you said.

表示(食物、天气、工作等)对...适宜

• The weather does not agree with me. 这种天气对我不适宜。
• Hard work does not agree with him. 艰苦的工作对他不适宜。

表示与...一致

• A verb must agree with its subject in person and number. 动词必须和它的主语在人称和数方面保持一致。
• What he does does not agree with what he says. 他言行不一致。

agree to...

agree to sth.

是指同意某计划、建议、或建议。

• Who else will agree to this suggestion besides him?
• We agreed to their arrangement. 我们同意了他们的安排。
• She agreed to marriage. 她同意结婚。

有时agree to也可用来表示答应一件自己不愿做的事:

• I was forced to agree to it, but at heart I didn't quite agree with it. 我被迫答应，但内心并不完全同意。

后接suggestion、plan、proposal等名词时，与accept同义。

• Do you think he will [agree to/accept] my suggestion? 你认为他会同意 (接受)我的建议吗?

agree to do.

do.为动词原形，表示同意去做某事。

• He agreed to go with us. 他同意与我们一起去。

agree to sb. doing.

此时to是介词，逻辑主语sb.可以省略，省略后等同于agree to sth.。

• I never agreed to Mary marrying him. 我从来没同意玛丽嫁给他。

agree on...

agree on...指在某方面取得一致的看法或达成协议。

• We agree on leaving for Beijing the next day. 我们就第二天出发去北京达成了一致。
• We agreed on the price. 我们就价格达成了一致意见。
• Both sides agreed on these terms. 双方都同意这些条件。

容易犯错的地方

agree不能接不定式的复合结构，所以汉语的同意某人做某事，不能直译为agree sb. to do. sth.，而应根据情况改用其它结构。

他们同意我去。
正: They agreed to let me go. 
正: They agreed to my going. 
误: They agreed me to go.

agree、coincide、correspond都含和谐一致的意思。

agree