Spanish speakers can sometimes understand entire phrases in ancient latin, depending on the words used.
For example in Civilization V, Agustus says:
“Salve. Augustus sum, imperator et pontifex Maximus romae”
Which is clearly “Saludos, Augusto soy, emperador y pontifice maximo (de) Roma”.
(“Hail, Augustus I am, Imperator and pontifex maximum of Rome”)
And in civ VI Trajan says:
“ave viator. augustae romae imperator caesar traianus sum. quis es? qua terra patria vocas?”
Again in Spanish:
“Ave, viajero, Augusto y Emperador (de) Roma Cesar Trajano soy, Quien eres?, Cual tierra es la patria vuestra?”
(“Hail, voyager, Agustus and Emperor of Rome, Caesar Trajan I am, Who are you? What’s your homeland?”)
As a Spanish speaker I had no trouble understanding those phrases because the words and grammar in those specific examples have not changed much in 2000 years.
However something like Cicero’s:
“Quae cum ita sint, Catilina, perge, quo coepisti, egredere aliquando ex urbe; patent portae; proficiscere. Nimium diu te imperatorem tua illa Manliana castra desiderant. Educ tecum etiam omnes tuos, si minus, quam plurimos; purga urbem. Magno me metu liberabis, dum modo inter me atque te murus intersit.”
Is practically unintelligible.