William Strunk Jr. — Elements of Style: Words often Misspelled

VI. WORDS OFTEN MISSPELLED accidentally     formerly      privilege advice     humorous     pursue affect     hypocrisy     repetition beginning      immediately      rhyme believe      incidentally      rhythm benefit      latter      ridiculous challenge      led      sacrilegious criticize      lose      seize deceive      marriage      separate definite      mischief      shepherd describe      murmur      siege despise      necessary      similar develop      occurred      simile disappoint      parallel      too duel           Philip      tragedy ecstasy      playwright      tries effect      preceding      undoubtedly existence      prejudice      until fiery      principal Write to-day, to-night, to-morrow (but not together) with hyphen. Write any one, every one, some one, some time (except the sense of formerly) as two words.