The meaning of this sentence depends strongly on context. 旅行ã¯ã„ã„ã§ã™ã‹ (ryokou wa ii desu ka) would probably be used to mean "is the trip/travel good?", but could also be a way of asking permission to travel.
If 'can' is to ask for permission etc, you can say 'haitte mo ii desu ka?'. If 'can' is used literally to mean 'to be able to' you can say 'haireru desu ka?'.
hittori de itte ii desu
sanpatsu ga ii desu ne!
Ii keshigomu desu, ne?
You mean 'borrow'. Can I borrow <thing here> would be: <thing here> wo karite ii desu ka?'.
The phrase "Anata no nihongo wa tottemo ii desu yo, dokode neruimashitaka" translates to "Your Japanese is really good, where did you learn it?" It expresses a compliment about someone's Japanese language skills and inquires about their learning source.
'Dete mo ii desu.'
itsu demo irashatte ii desu ga
You may say "dekakete mo ii desu ka."
これは会えですよ (kore ha ae desu yo) is like saying "This is a meeting".
Anata WA ii desu ka?- Which means in technical terms: Are you okay?
You may say 'ii sensei desu,' written in Japanese: いい先生です