Yes.
Period. Yes, you do.
Yes, i.e. Mr. , Mrs.
Mr. and Mrs. take a period, but Miss does not at it is not an abbreviation.
You put a period after all of those in the states, however, the British system requires no period after such abbreviations, Mr Mrs Ms .
Yes, Mrs. has a period because it is an abbreviation and mrs is not a word. The same holds true for Mr., Dr., and Ms.
You would say the male title first, but you need and in there. It should be Mr. and Mrs. John, and Mr. needs a period.
No, just use one space.
I would address it to Mr and Mrs David Keys. For the salutation I would use Dear Mr and Mrs Keys.
Yes. It would be appropriate to say "Mr. and Mrs. Smith" for example.
Mr. used to be acceptable to address a household by just using the last name, e.g. "Mr. Jones". In modern times, it is typically to use "Mr. and Mrs. Jones" or "Mr. and Mrs. Timothy Jones".
Mr and Mrs
In the inside address of a formal letter, you would typically write "Mr. John Smith and Mrs. Jane Smith" to address both individuals. If you are referring to them collectively, you might write "Mr. and Mrs. Smith." Ensure to include any titles or names as appropriate for the context of the letter. Always use proper punctuation, such as a period after "Mr" and "Mrs" if adhering to American English conventions.
Mr and Mrs is correct or Mrs and Mr is correct