"Healthy girls go to school."
Translation:Puellae sanae in ludum eunt.
"go to school" is an idiom. We go "to" school, not "in" school.
As "in ludum" is the way to say it in Latin, and is not particularly an idiom, but the logical way to say it, but "ad ludum" is also possible.
Could someone tell me if using "ad ludum" insists more on the move, that "in ludum"?
To me "ad ludum" stresses the journey and "in ludum" stresses the arrival / end of the journey. If the sentences were longer / had context, I would imagine something like:
Mane domo abimus. Ad ludum imus sed primum in foro visitamus. Hic panem emimus. Tunc ab foro eximus et in ludum inimus.
Iʻd be curious if otherʻs have thoughts on this.
Excellent example; please enjoy a lingot (audīvī lingotōs dēlectābiliōrēs cum cassiā saccharōque esse)! Now, whether or not it is correct, I cannot tell without going deeply into my dictionary and grammar, but it reads well to my somewhat trained eye (at half one in the morning).
Here is a plain-English overview of what the cases are and how they work:
Latin cases, in English
Adjectives must agree in gender, number, and case with the nouns they modify, but they have their own declensions. Sometimes you get lucky and the adjective just happens to follow the same declension as the noun, but that is not a guarantee.