They both didn't do their best.是全部否定还是部分否定？

Not both of them... 和Both of them didn't...才是部分否定？
但我很肯定地见到Not all men are clever=All men are not clever,那么Both of them didn't...怎会是全部否定呢？

They both didn't do their best.是全部否定还是部分否定？ 他们都是,是both are they 还是 they both are? They looked both ways before they crossed the street They were very tired,but they didn't____working. Now that they both are finoing中的finoing是什么意思？ Both of them与 They borh相同吗 the difference between counselor & consultant when they both mean 顾问 they didn't want to part from each other We didn't do it ____ they do now. They didn't do as well as they should have