[*] 197. Several verbs add some of the personal endings of the present system directly to the root,1 or combine two verbs in their inflection. These are called Irregular Verbs. They are sum , volō , ferō , edō , dō, eō , queō , fīō , and their compounds. Sum has already been inflected in § 170.
1 These are athematic verbs, see § 174. 2.