This category is considered as a joint category since two categories - the person and number - are closely connected with each other and are realized with the help of one marker (-s). Therefore this category represented by two member-opposition: 3-d person sg.:: non-3-d person sg.
In English the expression of this category is confined to the indicative mood an devided into 3 subgroups:
- include the modal verbs which have no personal inflexion. The category of number is neutralized
- is made up by the unique verb to be which has 3 different suppletive forms for different persons(am, is are). The verb to be is more grammaticalized than any other verb. In past tenses the verb to be doesn't have person, only number.
- presents the regular expression of person and number with remaining multitude of English verbs.