Her brother, who is majoring in business administration, told her several interesting facts about marketing. The 'shower effect' is a marketing technique that places theaters, culture centers, restaurants, and other facilities that consumers frequently visit on the higher floors of a building. On the contrary, the 'fountain effect' places restaurants and grocery stores where people often visit on underground floors, guiding visitors to be exposed to attractive goods on the first floor. (from a textbook in my country)
The two bold parts have the same construction. I wonder which relatives are possible for the italicized. Especially, I doubt whether the usage of 'where' is grammatically correct.
- theaters, culture centers, restaurants, and other facilities that consumers frequently visit
- theaters, culture centers, restaurants, and other facilities which consumers frequently visit
- theaters, culture centers, restaurants, and other facilities where consumers frequently visit
- restaurants and grocery stores that people often visit
- restaurants and grocery stores which people often visit
- restaurants and grocery stores where people often visit
I guess 3 and 6 are ungrammatical. People visit stores. 'Stores' is an object of the verb 'visit'. So in the sentences in question, we should use relative pronouns 'which' and 'that', not a relative adverb 'where'. But an online grammar checker says 'where' is okay and 'which' is not. I don't get why. Please help me.