instruction: Is the next sentence syntactically and semantically acceptable?

George sang to himself.
OPTIONS:
- unacceptable
- acceptable

response: acceptable

instruction: Is the next sentence syntactically and semantically acceptable?

I heard that Mary hired someone.
OPTIONS:
- unacceptable
- acceptable

response: acceptable

instruction: Is the next sentence syntactically and semantically acceptable?

Bill floated into the cave.
OPTIONS:
- unacceptable
- acceptable

response: acceptable

instruction: Is the next sentence syntactically and semantically acceptable?

I wonder to how many people Bill talks.
OPTIONS:
- unacceptable
- acceptable

response:
acceptable