Allen and Greenough's New Latin Grammar for Schools and Colleges
J. B. Greenough, G. L. Kittredge, A. A. Howard, Benj. L. D'Ooge, Ed.

[*] a. The personal pronouns are not expressed as subjects, except for distinction or emphasis:—

1. tē vocō, I call you. But,—
2. quis mē vocat? ego tē vocō, who is calling me? I (emphatic) am calling you.

[*] b. The personal pronouns have two forms for the genitive plural, that in -um being used partitively (§ 346), and that in -ī oftenest objectively (§ 348):—

1. mâior vestrum, the elder of you.
habētis ducem memorem vestrī, oblītum suī; (Cat. 4.19), you have a leader who thinks (is mindful) of you and forgets (is forgetful of) himself.
2. pars nostrum, a part (i.e. some) of us.

[*] Note 1.--The genitives nostrum , vestrum , are occasionally used objectively (§ 348): as,— “cupidus vestrum” (Verr. 3.224) , fond of you; “cūstōs vestrum” (Cat. 3.29) , the guardian of you (your guardian).

[*] Note 2.--“One of themselves” is expressed by ūnus ex suīs or ipsīs (rarely ex sē ), or ūnus suōrum .

[*] c. The Latin has no personal pronouns of the third person except the reflexive sē . The want is supplied by a Demonstrative or Relative (§§ 296. 2, 308. f）