Can an English name have only one letter?

English letters, like Chinese characters, can't be used as a word or Chinese characters (except' a' and' a').

some foreigners' names are abbreviated for convenience, such as the Canadian actress A.J. Cook, whose real name is

Andrea Joy Cook. It seems that there is no single letter.

If you have to use letters, it's better to use two or more letters, which is more comfortable to read. When explaining to others, just call it an abbreviation, such as SYJ.