agree with vs agree on vs agree to 

agree with

누구누구 의 의견에 동의하다, 어떤것에 대해 동의하다. 

(when you agree with someone/something, it means that you accept the point of someone/something.)

활용 형태) agree with somebody

활용 형태) agree with something

예) I agree with you.

예) Matt does not agree with my answer.

agree on

(이슈나 토론 내용에 대해) 합의가 되다, 의견이 일치하다.

(You agree on some issue or point of debate.)

활용 형태) agree on something

예) We agreed on this issue.

예) Major EU states agree on tighter regulation                                                                                                                                     

agree to 

(요구사항이나 요청 등을) 승낙하다

(You agree to demands/queries)

활용 형태) agree to something

예) He agreed to my request.

예) We agreed to her suggestion

예) Do you think he'll agree to their proposal?