posted by rfvv .
1. He wrote me a letter.
2. I was written a letter by him.
3. A letter was written me by him.
4. A letter was written for me by him.
(#1 is an active voice sentence. The others are passive voice sentences. Is #1 wrong or right as a passive voice sentence of #1? What about #3 and #4? Do we have to use 'for' before 'me' as in #4? Would you like to let me know the websites containing the information like that. Thank you.)
Only #4 is correct as the passive for #1.
First of all, read about indirect objects. That's what these forms are that you're asking about, regarding the use of "to" and "for."
In #1 with its ACTIVE verb, "me" is an indirect object. But when you put the same ideas into a PASSIVE sentence, the indirect object construction won't work anymore. Therefore you need to use "to" or "for" with the former indirect object.