To begin with my English skills, I am a published author of fiction and currently have a novel under consideration with a UK publisher. Plus I was a journalist for over 8 years, working with the two most prestigious English-language newspapers published from Kolkata. I have been freelancing as a proof-reader and editor for the last 18 years with outstanding results.
A word about by job completion rate, here at Freelancer. I have had the bad luck to run into unscrupulous clients who shifted the goalposts as soon as the job took off. To give you an example: a client who wanted some trancriptions done said he would pay me $0.05 per audio hour, whereas during our pre-award conversation I was given to understand that I would be paid $0.05 per hour put in per transcription. There are others who changed skill requirements after the job was awarded to me.
I have worked for Elance/Upwork for 11 years and never had a complaint against me and I built up a near perfect all-5 record on that site. You can rely on me.