The 15 Punctuation Marks in Order of Difficulty - Infographic | Writing | Scoop.it
Ever wonder why you can't figure out when and where to stick a comma? It's probably because commas, by far, have more rules and applications than any other punctuation mark. But why do so many people use the semicolon incorrectly? Comparatively, it should be one of the easiest punctuation marks to master. And why doesn't anybody seem to use the en dash?

Via Ana Cristina Pratas, Deanna Mascle