If you speak frankly, you state or express things in an open and honest way.
You can talk frankly to me.
你可以坦率地跟我谈。
You use frankly when you are expressing an opinion or feeling to emphasize that you mean what you are saying, especially when the person you are speaking to may not like it.
'You don't give a damn about my feelings, do you.'—'Quite frankly, I don't.'
“你一点也不在乎我的感情,是吧。” “坦率地说,是的。”
Frankly, Thomas, this question of your loan is beginning to worry me.
坦率地说,托马斯,你贷款的问题开始让我担忧。