首先的英语高级表达有：

1、in the first place。

2、first Relative explainations。

3、begin、、with。

4、for one thing、、(for another)。

5、first of all。

6、to begin with。

7、imprimis。

8、in the first instance

9、firstly

10、of all things

11、above all

12、to start with

13、primarily

14、threshold

15、at a first brush

16、first and foremost

17、the first thing

18、in the beginning

Examples:

那不是个好办法,首先没人会帮我们的忙.

It is not a good idea.For one thing,nobody will help us.

我首先是一个教师,其次才是一个作家.

I am a teacher in the first place and a writer in the next place.

婚姻首先是一种契约,它必须以公正为制约.

Marriage is,first of all,a contract which must be governed by justice.