Hello Harry! ^^ Thank you for submitting your homework today. Kindly take note of the corrections that I made. Thank you! ^^

Harry: hello I am harry I want to introduce about vallentine's day.vallentineday is form a minister and in vallentines day we have to give chocolate or candy when ilove her(him).the girls give chocolate to boy and the boys give chocolate to the girls.they says to each other "thank you" thank you for reading my letter and thankyou for my teacher. goodbye!!

Correction: Hello! I am Harry and I would like to introduce about Valentine's Day. Valentine's Day is named after the Saint Valentine. On Valentine's day, people love to give chocolates and other special gifts to each other.  The girls give chocolate to boys and the boys give chocolate to girls. They thank each other and give a "Thank you" letter to each other.

Explanation: A sentence should always start with the capital letter of the word. Be careful with the spelling and repetition of words.