Question

紧急！看一下这两句话有语法错误么，如果有拜托给改一下，紧急，在线等着回复。

From the above, not only some Polite Language is known, but also the reason of the differences between China and western is understood.这句话有语法错误么？
It is essential for keep these differences in mind and pay attention to them when communicating in foreigners.这句话也是有语法错误么？
真的很紧急拜托了

Answer 1

第一句：
当not only放在句首，连接一个句子时，该句应使用倒装语序；而but also后面的句子仍用陈述语序。所以，这句话应该改为-From the above, not only is some Polite Language known, but also the reason of the differences between China and western is understood.
第二句：
essential的其中一个用法是：it is essential（for sb）to do sth，所以应该为-It is essential to keep these differences in mind and pay attention to them when communicating in foreigners.

Answer 2

1.Not only … but also 连接两个分句，并且 not only 位于句首时，第一个分句中的主语和谓语要部分倒装。例如：

　　Not only does the sun give us light but also it gives us heat.

　　Not only did he speak English correctly， but also he speaks it fluently.
2.It is essential for keep：for是介词啊 后面怎么可能是动词原形 所以一定不对 is essential（for sb.）to do sth. 就可以了

Answer 3

第二句：

It is essential for sb to keep these differences in mind and (to ) pay attention to them when communicating with foreigners.