I'd like to what form of the verb must I use to write a letter ?
You question is too brief to get a possible answer (at least from me).
my opinion is to use present simple khalef thanks
I think like Gee. your question is too brief. However, general rules of writting is nearly the same as any writting in any other languages.
From majaxilin: I'd like to what form of the verb must I use to write a letter ?
i'd like the course for technical english
My letter to you:
thank you for your insteresting one-sentence letter from the 13. of february 2008. I must apologize (present tense) to answer this late, but I was (one month ago: past tense) on a workshop far away in the north of my country. Now I am back (present tense) and I am (present tense) ready for writing to you. I hope (present tense) you are fine now (present tense) and all your concerns are meanwhile removed (present tense, passive voice). Hopefully you will answer soon (future tense).