The article "I won’t hire people who use poor grammar" http://blogs.hbr.org/cs/2012/07/i_wont_hire_people_who_use_poo.html by Kyle Wiens says that if people can’t pass the grammar test they won’t be hired. They have a "zero tolerance" policy for poor grammar. They believe that a person should have at least high school English knowledge and know the difference between to and too. Even though ifixit isn’t all about writing they have all their positions take a grammar test. He believes that people who don’t care about writing are more likely” to think lots other things also aren’t important”. That would be why they give grammar test to all employees before they hire them.
After reading this article I would have to agree with some of their arguments and then disagree about other arguments they had. I also believe that people who make fewer mistakes in a grammar test would make fewer mistakes on the job. One thing I did disagree about was applicant who was perfect for the job but failed the grammar test. You could give that person grammar lessons to improve their writing. Then they could re take the grammar test after some lessons so you would know that they have the proper writing skills for the position.