同意某人的意见用英语可以说成 "I agree with someone" 或者 "I concur with someone"。
"I agree with" 是英语中常用的表达方式，意思是“我同意”。这个短语可以接在名词或者代名词后面，如"I agree with you" 意思是"我同意你"。
"I concur with" 是“同意，一致”的意思，常用于正式场合，类似于“I agree with”。
例句：
I agree with his suggestion. (我同意他的建议)
I concur with your assessment of the situation. (我同意你对这种情况的评估)