Every time you make a typo, the errorists win. – Author unknown

[T]he flesh of prose gets its shape and strength from the bones of grammar… – Constance Hale, Sin and Syntax: How to Craft Wickedly Effective Prose, 1999

The writer who neglects punctuation, or mispunctuates, is liable to be misunderstood for the want of merely a comma, it often occurs that an axiom appears a paradox, or that a sarcasm is converted into a sermonoid. – Edgar Allan Poe

[B]ut why care for grammar as long as we are good? – Artemus Ward (1834–1867), Pyrotechny, “V.—What This Young Man Said”