The sentence
FELIS ANTE FENESTRAM INTER CANES CURRIT
has ‘FENESTRAM’ in the accusative because ANTE and INTER
are special cases where the accusative governs there use
if you remove ANTE and INTER from the sentence and ‘The
dog in the window runs’ is the new sentence then window
would be in the ablative and written FENESTRA
Correct?
Thanks.
Hi BwCN,
it would rather depend on what you mean with ‘in the window’.
Is the dog crashing into the glass? If yes, use ‘in + acc’.
Is the dog running through an open window? if yes, use ‘per + acc’
The point really is that when you are talking about movement, you will generally use a preposition with the accussative.
If the action or scene described is static, use a preposition with the ablative.
As you have noted, the prepositions ante and inter only take the accusative. They are therefore quite naturally associated with movement.
And i suppose if it was ‘The dog is in the window’ it would
be the same as ‘The dog is in the house’ and use the
ablative?
Thanks.
Correct! 
If the accusative governs motion and the ablative governs location
then i guess it is just an exception that PRO SINE and SUB are
goverened by the ablative when expressing motion
Thanks.
sub uses the ablative when expressing location under and the accusative when expressing motion under.
as for pro and sine, which both take the ablative, they do not indicate motion.
pro literally means “to be in front of” and idiomatically means “for”.
sine means “without” and so it has no sense of motion involved with it.
they may both be used in phrases that have motion involved, but the prepositions themselves do not indicate motion, unlike in, ad, sub.
By the way, do you see that “felis” is the subject of the original sentence, blutoonwithcarrotandnail, and not “canes”? What you said (“if you remove ANTE and INTER from the sentence and ‘The dog in the window runs’ is the new sentence”) suggests otherwise. We know the subject is singular from the verb (“currit”),—“felis (cat)” is singular and therefore the subject (“the cat runs”), whereas “canes (dogs)” is plural and therefore cannot be the subject.
You know, also, that “ante fenestram” is not like “anti” in English,—it doesn’t somehow mean “against the window”,— but it means “in front of” or “before” or “in view of the window” and “inter” means “between” or “among the dogs”
Obiter, intellegesne, canorcaerulecarotâclavoque, “felis” subjectivum huius sententiae esse. Quod dixisti (“if you remove ANTE and INTER from the sentence and ‘The dog in the window runs’ is the new sentence”) contrarium perperà m indicare credo. Singulis numeri subjectivum est, id quod “currit” verbum nobis ostendit. “Felis” solum numeri singulis est, cum “canes” pluralis.
Et “ante” praepositionem latinè sicut “anti” anglicè non esse cognovisti, ut spero.