I would like to know if it is grammatical and appropriate to finish an informal letter "I must bring to a close now." My gut feeling tells me if at all, it should be "I must bring IT (or my letter) to a close." I'm also interested whether this form really exists, as it seems to me to be either old (old-fashioned) or simply formal.
Thanks very much for your help!
It's not necessary to say this sort of thing in any sort of letter. After all, it's pretty obvious to the reader that it's the end of the letter. However, if you do want to say something like that, then you could write "I must stop now, because .....it's getting late/so that I can post this/I must make dinner etc etc"
I'm not a teacher of English, but I have spoken it for (almost) all of my life....