instruction: Is the next sentence syntactically and semantically acceptable?

Tonight, what Bob cooked yesterday still tastes good.

response: acceptable


instruction: Is the next sentence syntactically and semantically acceptable?

Who do you think that believes John to be innocent?

response: unacceptable


instruction: Is the next sentence syntactically and semantically acceptable?

Robin arrived partway at the station.

response: unacceptable


instruction: Is the next sentence syntactically and semantically acceptable?

Ron heard a discussion in the foyer

response:
acceptable