“Personal” in grammar means “relating to person,” that is, first, second, or third person. In English, those persons are represented by pronouns: I, you, he, she, it, we, ya’ll, they. These MUST look familiar as they are forms we’ve already studied in relation to verbs. Now we’ll look at them independently as pronouns. So, how does Latin treat these forms, not as verb endings but as nouns? There is a caveat: they decline through cases as nouns do in Latin, so you have more to memorize. 

Remember how we studied that “boy” in Latin goes puer, nominative singular (subject); pueri, genitive singular, “of the boy;” puero, dative singular, “to/for the boy.” Of course you remember that! 

But why would Latin have a nominative singular for “I” and “you” at all. Aren’t those pronouns embedded in the verb? Why would you need to say ego, when amo and video by their very nature indicate first person singular? 

In English we have to say “we” if we want to indicate that “we” is the subject, right? But that same information is embedded in every Latin finite verb, that why, in a sentence, if there is no clear Nominative subject, we look to the verb to supply our subject (i.e. “I”, “you”, etc.). So the Romans didn’t use their nominative personal pronouns to explain what the subject is; rather, they used them to emphasize it.

For instance, if we said in Latin tune amas? “Are you in love?” In this case, the Latin speaker would be emphasizing the subject, “you,” by including the Latin nominative personal pronoun tu.

I can’t leave ego and tu without talking a little linguistics. If linguistics bores you, stick your fingers in your ears for the next two minutes. Because personal pronouns are commonly used forms in Indo-European languages, they reveal some interesting features of the evolution of those daughter languages which developed out of the mother tongue that Latin and English share: Proto-Indo-European. Originally, the Latin word ego and the English word “I” were the same word. Both evolved from a form that looked like ego ─ so Latin actually changed the form of this pronoun very little ─ but in English the inherited -g- transformed at some point into a /kh/ sound. This ended up as a form that sounded like /ik/ which is still the Dutch word for “I,” cf. German ich. English eventually dropped the -k-, lengthened the i-, and we ended up with our first-person singular personal pronoun. The same interchange between -c- and -g- can be seen in our word “cold” and the Latin word gelidus, both from an Indo-European base that means “frozen.” Also, English “kin” and Latin gens come from a single Indo-European word that meant “family.” A comparable pattern of change explains tu in Latin and “thou,” the archaic English form of “you.” Indo-European t- remained as t- in Latin, but in English it evolved into th- ─ thus, tu and “thou.” They were once the same word. You can see the same pattern in the word for “mother:” Latin has mater, English has “mother.” Likewise, the word for “tooth,” where Latin has dentes, English has “teeth.”