Dear Sir or Madam,
Writing your autobiography for your 4 grandkids is an excellent idea; I wish that one of my grandparents had done the same for me, and I would be delighted to help you with this project. First of all, I would like to assure you that as a fellow North American and a native English speaker, my command of the written language is extremely strong. My score of 93% on Freelancer.com's US English Level 3 test illustrates that my grammar, punctuation, and spelling are virtually flawless (even without the use of my Microsoft Office 2016 software), and that I have the ability to find and fix any and all errors in both sentence and paragraph structure. My vocabulary is immense, and I am capable of finding the perfect replacement if I find any words that are misused, incongruous, or that become too repetitive. If I edit your autobiography, I will be very careful not to leave any trace of my own style behind, and will not use words that do not fit in with your unique written voice.
I am writing a well-thought-out bid, and not a form letter, because I take a great deal of pride in my work. Should you choose me to edit your autobiography, I will put as much time, effort, and care into it as I would put into writing my own autobiography. I like to be available via messenger to my employers to make sure they are 100% satisfied with my work as I go along, and I will make any changes you desire. Please message me with any questions or to discuss details.
ElectricInk