It's called the same thing in Latin grammar; although it's referred to as the "nominative case" instead of the predicate nominative.
In Latin, the nominative case is used for the subject of a sentence or the predicate nominative, which renames or identifies the subject. It is also used with certain verbs that do not take a direct object.
The noun after the verb is the predicate nominative. John is boss. Boss is the predicate nominative.
It all depends on what its use in the sentence is, but in nominative case (subject/predicate nominative) it would be frater tuus.
A nominative case (subjective) pronoun is used as the subject of a sentence or a clause and as a predicate nominative.
Nominative Case The nominative case is the form of a noun or pronoun used in the subject or predicate nominative. In English this is significant only with personal pronouns and the forms of who. Personal pronouns in the nominative case in modern English are I, you, he, she, it, we, and they. The word who is also in the nominative case.
A predicate nominative is a noun or a pronoun. A predicate noun is a noun.
Latin is case sensitive for all of its nouns, pronouns, and adjectives. The use of each noun or pronoun in a sentence determines what case ending the noun or pronoun will have. For example, if the noun is used as a subject or as a predicate nominative, it will have a nominative case ending. So also in the case of a noun used as a direct object, the noun will have an accusative case ending appended.
Friends is a noun, so it's a predicate nominative.
"Sum me."sum ego is correct (the objective pronoun me is not to be used as a predicate nominative).
Pie is a noun. If it follows a linking verb, it's a predicate nominative.
A predicate nominative is a noun or pronoun that follows a linking verb. Crate is a noun, so it can be used as a predicate nominative. Example: That is a crate.
In Latin, the "nominative" case refers to the subject.