Subject of filia est Iulia

I’ve started with D’Ooge’s Latin For Beginners but I cannot work out the grammar of the exercise in section 22. The book translates “Filia est Iulia” in the third question as “His daughter is Julia”. Since in English the pronoun “His” is the subject of this sentence, my understanding is that “est” in the Latin implies a possessive pronoun which would be the subject of that sentence and “Iulia” is the object. Textkit’s key for the exercises has “Filia” as the subject and no object. Have I misunderstood how this sentence works? Can the copula not imply a pronoun?

The “his” in the English translation is not implied by the “est” but rather by the context: When talking about someone’s / your own family member (or a body part) in Latin, you don’t have to say who it belongs to because the context makes it clear.

Consider this example from Plautus’ play Amphitruo, where a character says the following after being perplexed by thunder and lightning: “caput dolet, neque audio, nec oculis prospicio satis”

“caput dolet” literally means “(the) head hurts”, but in English we would naturally say “my head hurts”. We do this because a) we know whose head it is, and b) because this is how such a thought is typically expressed in English.

By the way: “his” is NOT the subject of the English sentence. The subject is “(his) daughter”, just like in Latin.

I hope this helps!

LM’s answer is good. Additionally, intransitive verbs like the copula don’t take direct objects, but predicate nominatives. In your sentence, Iulia is the predicate nominative.

Thanks, now I get it. Is there a recommended primer on English grammar to go through in order to pick up Latin easier?