How to demonstrate my skills as an expert English editor in a cover letter?

[deardipu]

Sundus, 

A verified 'Ieltes' certification would be great to demonstrate your English competent. By then, you may inform it in a cover letter. 

[prestonhunter · Accepted solution]

re: "How to demonstrate my skills as an expert English editor in a cover letter?"

You should not have a cover letter.

If you apply to a job posting, you don't send a cover letter. You send a proposal.

The proposal is NOT ABOUT YOU.

The client doesn't care about you.

Write about what the client cares about:

a) the client's project

b) how you will make the client's life better by working on the project

If the client wants to know more about you, he will read your profile page.

If you want to demonstrate your skills as an expert English editor, then you will post items in your Upwork portfolio.