Learn Finnish: Pidimme ylellisestä hotellista hienoine ravintoloineen. - We liked the luxurious hotel with its fine restaurants.

In the comitative case, modifiers like adjectives (here, hieno) take the -ine ending to agree with the noun, but they never take a possessive suffix. Only the main noun (ravintola) takes both the comitative -ine- marker and the possessive suffix (-en).

What possessive suffix is used at the end of ravintoloineen?

The suffix is -en, which is a form of the third-person possessive suffix (meaning his, her, its, or their). When attached to the comitative ending -ine-, the third-person suffix is always -en rather than -nsa or -nsä. Here, it translates to its, referring back to the hotel.

Does ravintoloineen inherently mean multiple restaurants?

Usually yes, but technically the comitative case is always built on the plural stem, which includes the plural -i- marker. Because of this structural rule, hienoine ravintoloineen could theoretically mean with its fine restaurant (singular) or with its fine restaurants (plural). You have to rely on context to know which makes more sense.

Why are ylellisestä and hotellista in the elative case (-stä / -sta)?