"The two sisters are in Rome."
Translation:Duae sorores sunt Romae.
You may have already found out why by now, but for some who may not yet know:
Romae is the locative case and is not used with the preposition in.
Just to note that the locative case is only used with names of cities, towns, small islands (usually contain only one city or town), and a handful of other nouns like domus. All other nouns would make use of a preposition (like in with the ablative).
Locative exists only for names of cities and small islands (along with a handful of common nouns like "domus").
- So "In Rome" => "Romae" because Rome is a city and as such uses the locative case
- But "In Italy" => "In Italia" because Italy is neither a city nor an island but a country and, as such, does not use the locative case. To "replace" it, we use the preposition "in" followed by ablative.
Yes, it's correct. You can move the verb in Latin.
You have to know it changes a bit the meaning, changing the emphasis of some words.
Usually the verb comes at the end of the sentence.
But moving the verb elsewhere is also correct.
And "to be" is an exception, this word is more common in the middle of the sentence (or at the beginning).