Breakdown of O meu pai procurou o manual, mas não encontrou.
não
not / no
o pai
the father / the parents
mas
but
meu
my (m/f/pl: meu, minha, meus, minhas)
Questions & Answers about O meu pai procurou o manual, mas não encontrou.
Why isn't there a word for "it" after "encontrou"?
This sentence uses the inanimate null object (Complemento Direto Nulo). In European Portuguese, when a lifeless object like o manual is already clearly established in the sentence, you can completely omit the direct object pronoun. Instead of saying mas não o encontrou, you can simply say mas não encontrou.
If I did want to include the word for "it", how would I write the second half of the sentence?
You would use the direct object pronoun o to replace o manual. Because the negative word não is a "magnet" that pulls pronouns before the verb, it would become mas não o encontrou.
Could I also drop the pronoun if he was looking for a person?
Why is there an "O" before "meu pai"?
In European Portuguese, it is the standard rule to place a definite article (o or a) before a possessive pronoun. While you might hear meu pai without the article in Brazilian Portuguese or in very formal/literary European Portuguese, o meu pai is the natural, everyday way to say "my father" in Portugal.