To create parallel structure in the sentence, which phrase would best replace the words "only to offer dinner"?
Restaurants that offer live music are more entertaining than only to offer dinner.
restaurants offering only dinner
having restaurants offering only dinner
restaurants that offer only dinner
dinner-only restaurants
To maintain the parallel structure, we use "restaurants that offer only dinner", since the first part of the sentence uses "Restaurants that". So it is reasonable that you should also use "restaurants that" to correct the structure in the sentence.
