[Brian is writing graffiti on the palace wall. The Centurion catches him in the act]
Centurion: What's this, then? "Romanes eunt domus"? People called Romanes, they go, the house?
Brian: It says, "Romans go home. "
Centurion: No it doesn't ! What's the latin for "Roman"? Come on, come on !
Brian: Er, "Romanus" !
Centurion: Vocative plural of "Romanus" is?
Brian: Er, er, "Romani" !
Centurion: [Writes "Romani" over Brian's graffiti] "Eunt"? What is "eunt"? Conjugate the verb, "to go" !
Brian: Er, "Ire". Er, "eo", "is", "it", "imus", "itis", "eunt".
Centurion: So, "eunt" is... ?
Brian: Third person plural present indicative, "they go".
Centurion: But, "Romans, go home" is an order. So you must use... ?
[He twists Brian's ear]
Brian: Aaagh ! The imperative !
Centurion: Which is... ?
Brian: Aaaagh ! Er, er, "i" !
Centurion: How many Romans?
Brian: Aaaaagh ! Plural, plural, er, "ite" !
Centurion: [Writes "ite"] "Domus"? Nominative? "Go home" is motion towards, isn't it?
Brian: Dative !
[the Centurion holds a sword to his throat]
Brian: Aaagh ! Not the dative, not the dative ! Er, er, accusative, "Domum" !
Centurion: But "Domus" takes the locative, which is... ?
Brian: Er, "Domum" !
Centurion: [Writes "Domum"] Understand? Now, write it out a hundred times.
Brian: Yes sir. Thank you, sir. Hail Caesar, sir.
Centurion: Hail Caesar ! And if it's not done by sunrise, I'll cut your balls off.