A final consonant is not doubled when it is preceded by a diphthong, when the primary accent is either not on, or not retained upon, the last syllable, or when the additional syllable begins with a consonant; as, beat, _beating_, _beaten_; dif´fer, _dif´fering_, _dif´fered_, _dif´ference_, _dif´ferent_; prefer´, _pref´erence_; refer´, _ref´erence_; fit, _fitful_, _fitly_, _fitness_; ben´efit, _ben´efited_, _ben´efiting_. EXCEPTION I.—Compounds that remove the primary accent from the point of duplication retain the double letter; as, _broad´-brimmed_, _heel´-tapping_. _Remark I._—When _ly_ is affixed to words ending in _l_, the l is not considered doubled; as in _cool-ly_, _real-ly_, _gravel-ly_, _royal-ly_. _Remark II._—_Nutmegged_, _kidnapping_, _kidnapped_, _kidnapper_, _zigzagging_, _zigzagged_, _excellence_, and some others, are undisputed exceptions to the rule. There are nearly one hundred words, from which more than four hundred derivatives are formed, that are usually made exceptions to this rule. Webster is distinguished for making nearly all the derivatives conform to the rule. Webster and Smart accent the verb _curv´et_, on the first syllable, with which accentuation _curveting_ and _curveted_ are correct spellings; other orthoepists accent upon the last syllable, then _curvet´ting_ and _curvet´ted_ are correct. RULE VIII. Words ending in _c_ accept of _k_ before a termination beginning with _e_, _i_, or _y_; as, frolic, _frolicked_, _frolicking_; colic, _colicky_. ILLUSTRATIONS. colic colicky frolic frolicking frolicked havoc havocking havocked mimic mimicking mimicked mimicker physic physicking physicked rollic rollicking rollicked traffic trafficking trafficked trafficker talc talcky zinc zinckiferous (zinciferous) zincky RULE IX. Words ending in a double letter preserve it double after a prefix or before a termination beginning with a different letter; as, _op-press_, _mis-spell_, _in-thrall_, _oversee_; _see-ing_, _op-pressive_, _stiff-ness_, _woo-ed_, _still-ness_, _assess-ment_. _Remark I._—_Annul_, _until_, _twibil_, and the conservative _fulfil_, or the Websterian _fulfill_, are the only exceptions to the first part of this rule extensively recognized by present usage. The conservative _distil_ and _instil_ are at variance; but the Websterian _distill_ and _instill_, and also _twibill_, as written by Reid, are in harmony with the rule.