Keep in mind that this method works for regular verbs (verbs that follow the rules)
-ar
yo [-o] tú [-as] él/ella/usted [-a] nosotros [-amos] vosotros [-áis] ellos/ellas/ustedes [-an]
Examples: yo canto [I sing] tú cantas [you SING (singular informal)] él canta [he SINGs] ella canta [she SINGs] usted canta [you SING (singular formal)] nosotros cantamos [we SING] vosotros cantáis [you SING (plural informal)] ellos cantan [they sing (masculine)] ellas cantan [they sing (feminine)] ustedes cantan [YOU SING (PLURAL formal/informal)]
-er
YO [-O] TÚ [-eS] ÉL/ELLA/USTED [-e] NOSOTROS [-eMOS] VOSOTROS [-éIS] ELLOS/ELLAS/USTEDES [-eN]
EXAMPLES: YO COmo [I eat] TÚ comes [YOU eat (SINGULAR INFORMAL)] ÉL come [HE eats] ELLA Come [SHE eats] USTED come [YOU eat (SINGULAR FORMAL)] NOSOTROS comemos [WE eat] VOSOTROS coméis [YOU eat (PLURAL INFORMAL)] ELLOS comen [THEY eat (MASCULINE)] ELLAS comen [THEY eat (FEMININE)] USTEDES comen [YOU eat (PLURAL FORMAL/INFORMAL)]
-ir
YO [-O] TÚ [-eS] ÉL/ELLA/USTED [-e] NOSOTROS [-iMOS] VOSOTROS [-íS] ELLOS/ELLAS/USTEDES [-eN]
EXAMPLES: YO vivo [I live] TÚ vives [YOU live (SINGULAR INFORMAL)] ÉL vive [HE lives] ELLA vive [SHE lives] USTED vive [YOU live (SINGULAR FORMAL)] NOSOTROS vivimos [WE live] VOSOTROS vivís [YOU live (PLURAL INFORMAL)] ELLOS viven [THEY live (MASCULINE)] ELLAS viven [THEY live (FEMININE)] USTEDES viven [YOU live (PLURAL FORMAL/INFORMAL)]
If you want to learn more about spanish personal pronouns click here