This one is for you if you love unfinished sentences and thoughts, or if you sigh after every (written) phrase, or even in the middle of the phrase. Or, seriously, for omitted parts of a quotation, or for long lines between parts of text.
To type three dots in one hit on the keyboard, press Option (alt ⌥) and hit semicolon (;).
⌥ + ; = …
The 'posh' name for the three dots is ellipsis. To read all about it, go to this wikipedia article, which also shows and describes other punctuation signs.