87.say译为“说”tell sb to do

87.say译为“说”侧重讲说话的内容。
Say sorry/thanks /goodbye to sb对某人说抱歉/谢谢/再见
I often say hello to my teachers when I meet them.
We should say thank you to him when someone helps us.
tell.译为“告诉，讲述”，强调讲给别人听。
tell sb to do sth告诉某人做某事。
tell sb（about ）sth告诉某人关于某事。
The policeman tells the children not to play football on the street. It's very dangerous.
My grandma often told me stories when I was a child.