Frequent (spelling)
From Hull AWE
Frequently is one of the 117 mis-spellings listed as 'Common difficulties' in the section on 'Spelling' within 'Writing' in UEfAP.
The adjective frequent and the adverb frequently, as well as the verb 'to frequent' along with their derivatives, are spelled as shown here - despite their being pronounced with different stresses (see frequent (pronunciation).