please send me this letter fast, it is very important for me, i need a written by a Head of HR department to a infotech departant approving the changes introduced by the infotech department.
I'm sorry that you've misunderstood the purpose of the forum, but we don't write letters for people. You must write your own letters (or essays, etc.) and someone will take a look at what you write.
I'm not a teacher, but I write for a living. Please don't ask me about 2nd conditionals, but I'm a safe bet for what reads well in (American) English.