"An bhfuil fíon costasach agat?"

Translation: Do you have expensive wine?

[Fabitorti]

I answered costly instead of expensive but both adjectives have the same meaning, don't they?

[scilling]

They do.

[DavidKenny16]

Expensive is purely money. Costly is more general. For example it was an expensive divorce and it cost me my Dog.

[EileanoirCM]

"The more expensive the wine, the gooder it is also"

[Breandan2014]

I was really asking the question why can Duolingo not accept both 'dear' and 'expensive' as translations of costasach? I don't see that the origins of these words is relevant to how they are used in this translation.

[scilling]

They could accept both of them, but unless you use the Report a Problem button, the issue won’t come to the course creators’ attention.

[Breandan2014]

what is the difference between dear and expensive?

[scilling]

In the meaning of “having high price”, they’re synonyms. (“Dear” comes from Germanic roots, cognate to German teuer, and “expensive” comes from Latin roots.) “Dear” is also used to express affection, but “expensive” isn’t.