Should you use one space after a period, or two? I learned to type in the 1970s, on a manual typewriter, and our instructor was adamant that you must always press the spacebar twice at the end of sentence.
Fortunately, I learned the error of my ways in the 1980s (after I finished my Ph.D. thesis, which was printed on a monospaced daisy wheel clunker of a printer, and has double spaces everywhere): You may only use one space to separate sentences, or your readers will all scream and tear their eyeballs out, and bleed all over your copy.
There will be no argument on this matter.










