第二句语法不对，动名词形式主语与句子的主语不一致，不应省略。但是，说英语不是考试，你说清楚，别人明白就行了，千万不要纠缠细节。（谁能分析一下这句话的汉语结构有没有错误）
如果你不想当语言学家或政治家，就别在这事上下太多功夫。
When I first started working in an American company, my friend told me that I always corrected my grammar during my speech. He told me I should not be stopped by thinking of these mistakes. When you stop, your flow of thoughts is stopped, too. So, keep going with all your grammatic errors, they are acceptable.
However, if you always use "he" instead of "she", you may need to draw a picture in you mind when you speak. But, this is NOT a big mistake, either.
如果你不想当语言学家或政治家，就别在这事上下太多功夫。
When I first started working in an American company, my friend told me that I always corrected my grammar during my speech. He told me I should not be stopped by thinking of these mistakes. When you stop, your flow of thoughts is stopped, too. So, keep going with all your grammatic errors, they are acceptable.
However, if you always use "he" instead of "she", you may need to draw a picture in you mind when you speak. But, this is NOT a big mistake, either.