PERSON AND NUMBER.
235. The English verb has never had full inflections for number and person, as the classical languages have.
When the older pronoun thou was in use, there was a form of the verb to correspond to it, or agree with it, as, "Thou walkest," present; "Thou walkedst," past; also, in the third person singular, a form ending in -eth, as, "It is not in man that walketh, to direct his steps."
But in ordinary English of the present day there is practically only one ending for person and number. This is the third person, singular number; as, "He walks;" and this only in the present tense indicative. This is important in questions of agreement when we come to syntax.