Annual

Note the spelling of the adjective and occasional noun annual, with two '-n-'s and a '-u-' and an '-a-' in the final syllable. It can be confused by typing error (and spellchecker) with the verb 'to annul'. The derivation is the Latin annus 'a year', with its associated adjective annuus.

This is one of the 117 mis-spellings listed as 'Common difficulties' in the section on 'Spelling' within 'Writing' in UEfAP.