to start from square one: 上次没有成功，必须回到起点从头做起

3. to cut the cord: 意思是父母要让儿女离家过著独立自主的生活
(let your children leave home and become independent) (只用於父母与儿女间的关系);
例如： When your children are old enough to take care of themselves, you have to cut the cord.（当你的孩子长大可以照顾他们自己时，你就应该让他们自力更生。）(即切断依赖父母的脐带。)
It is very difficult for many Chinese parents to cut the cord with their children.（许多中国父母很难让儿女完全独立自主。）(注：这里的 cord，是指 umbilical cord 即脐带。）

4. to start from square one: 意思是上次没有成功，必须回到起点从头做起
(something did not succeed in the first place, have to start over again） (这与 to be back to square one 意义相同);
例如： He has to start from square one because his computer destroyed (crashed) his homework. (由於电脑搞坏了他的作业，他必须从头做起。)

The search committee for the new college president will have to start from square one.（选拔新校长委员会上次没有成功，现在又要从头做起。)
We are back to square one. (我们又从头做)