Write an application to your Principal, requesting for a testimonial.
To
The Principal,
St. John Public School,
Kidwai Nagar,
New Delhi.
Sir,
I passed my S.S.C. Examination last year from your school under Roll No. 2132 in the first division. My name appeared on the merit list. I won first prize in the inter-school declamation contest and second prize in the painting competition. There has never been a complaint against my character or conduct.
I shall feel highly obliged if you issue to me a character certificate highlighting the points mentioned by me above.
With deep regards,
(Date)
Yours obediently,
X.Y.Z.