Model Answer:

Dear Sir or Madam,

I am an international student in the United Kingdom, and I came on a student visa about two years ago from India. Since then I have been living in this great country and studying to finish my post-graduation degree. If everything goes fine with my studies and according to the schedule, I should be able to complete my degree in Civil Engineering this coming June, which is only a few months away from now. So, no problem there, and I would like to thank you again for that.

But, then, I am also thinking of continuing my education for another three months after finishing my post-graduation degree except, of course, the problem is, my visa is going to expire as soon as I finish my degree. By the way, I want to use these additional three months in pursuing a professional diploma course in “AutoCAD” since it very much aligns with my ambition to prepare myself as a fine Engineer. 

Now that you know why I want to stay another three months in your country, I would highly appreciate it if you grant me a visa extension for that period.  

Yours faithfully,

Chetan Singh