turn the corner

看到这个成语，你首先想到的大概是人在街上走，走到街角处转变上另一条街吧!不错，这正是这个成语的字面意义，但作为成语，它用在人在街道上的行走来比喻事态、局面的进展和变化，常用以指在事情的发展过程中产生了转机，脱离了危险的发展方向，走上了趋于正常的道路。它常用于病人脱离了危险或书面闯过了难关这样的情形：

The patient has awakened from the coma and his blood pressure is rising to normal. The doctor says he has turned the corner.
病人从昏迷中苏醒过来，血压也回升到正常，医生说他已脱离了危险。

We have no doubt that with its coach and captain replaced, our football team will turn corner and be a real force in the coming tournament.
我们毫不怀疑，更换了教练和队长后，我们这支球队一定能改观，成为锦标赛中的一支劲旅。

in the same boat

同乘一条船的人在很大程度上要经历同样的命运，他们或是一路顺风，大家一起平安地到达目的地；或是一起经受风浪，乃致遭受船毁人亡的厄运。因此，in the same boat这个成语便用来形容处于同一境遇，面临同样危险的人。我们汉语中的“同舟共济”和这个英语成语可以说是同出一辙。介词in也可以用on：

Talking to the employees, the boss emphasized that they were in the same boat; if everyone worked hard, the firm would survive; otherwise it would have to close down.
在对雇员们讲话时，老板强调说，他们是同舟共济的，如果大家好好地干，公司尚能生存，否则，公司只能倒闭。

Nearly all the pupils found chemistry especially difficult this term. After the exam, they felt that they were on the same boat.
几乎所有的学生感到这学期化学课特别难，考试以后，大家都感到同一命运。

Hitler’s aggressive policy put all the European countries on the same boat. So they decided to form an alliance to cope with the manace.
希特勒的侵略政策使所有欧洲国家面临同样的险境，于是他们决定建立同盟以抵御威胁。