天南海北的英文：
[Literal Meaning]
sky/south/sea/north
to be in the south of the sky and the north of the sea

[解释]
相距遥远。形容谈话漫无边际。

[Explanation]
(to separate) far and wide

[例子]
他天南海北地扯了很多，但是真正的意图却是想让我们放弃计划。

[Example]
He talked a lot discursively, but his real purpose was to let us quit our plan.

[英文等价词]
all over the country
rambling

One could hear every subject under the sun being hotly discussed
你们可以听到人们天南海北什么都谈得很热烈。