Questions & Answers about Nuntius dicit se verum dixisse.
Because dicit introduces an indirect statement (reported speech), and in Latin the subject of that reported clause is normally in the accusative.
- se is the reflexive accusative pronoun, meaning himself, and it refers back to the subject of the main verb (nuntius).
- Latin does not use ego in indirect statement here, because the speaker in reported speech is handled with se (if it refers to the main subject).
If the messenger were talking about someone else, you’d use a non‑reflexive accusative pronoun/noun, e.g. nuntius dicit eum verum dixisse = the messenger says he (someone else) told the truth.
It’s the standard Latin indirect statement construction: accusative + infinitive (often abbreviated AcI).
So se = accusative subject of the infinitive, and dixisse = the infinitive verb of the reported statement.
In indirect statement Latin uses an infinitive where English often uses that + a finite verb.
dixisse is the perfect active infinitive of dico, dicere. It means to have said / to have spoken (i.e., the saying happened before the time of ).