instruction: Is the next sentence syntactically and semantically acceptable?

The architect selected a house for the couple.

response: acceptable

instruction: Is the next sentence syntactically and semantically acceptable?

What happened was they went home.

response: acceptable

instruction: Is the next sentence syntactically and semantically acceptable?

Which room did John see the man in?

response: acceptable

instruction: Is the next sentence syntactically and semantically acceptable?

Fred watered the plants flat.

response:
acceptable