Ego

Ego is the first person singular nominative pronoun. The first person plural nominative is nōs. Thankfully, the declensions of these personal pronouns are similar enough to the other declensions, see here: Latin Declensions.

SingularPlural
Nom.egonōs
Gen.meīnostrum/nostrī
Dat.mihinōbīs
Acc.nōs
Abl.nōbis

Similar to Ego, is the second person singular nominative pronoun, while vōs is the plural.

SingularPlural
Nom.vōs
Gen.tuīvestrum/vestrī
Dat.tibivōbīs
Acc.vōs
Abl.vōbis

Is, Ea, Id

Is, Ea, Id are the third person pronouns in the male, female and the neuter respectively. Unlike, ego and tū, we use the genitive of Is, Ea, Id to show possesion; for ego and tū, we use the possessive adjectives. Finally, the demonstrative Īdem, eadem, and idem, meaning the same, are formed by adding -dem to the endings below.

SingularPlural
Nom.iseī/iī
Gen.eiuseorum
Dat.eīs
Acc.eumeōs
Abl.eīs
SingularPlural
Nom.eaeae
Gen.eiusearum
Dat.eīs
Acc.eameās
Abl.eīs
SingularPlural
Nom.idea
Gen.eiuseorum
Dat.eīs
Acc.idea
Abl.eīs