Dear Sir/Ma,
I write to apply to your advertisement for an article writer.
Writing is one of my hobbies. I have written a number of unpublished novels. Being from an English speaking country, I have a good command of the English language. I am proficient in MS Word and, I am time conscious.
It is my believe that I have the skills and expertise required to successfully execute this job to your utmost satisfaction.
I look forward to a positive reply.
Thank you.
Best Regards,
Paul.