instruction: Is the next sentence syntactically and semantically acceptable?

I will read linguistics for an hour.

response: acceptable

instruction: Is the next sentence syntactically and semantically acceptable?

John will study syntax, and Mary, too.

response: acceptable

instruction: Is the next sentence syntactically and semantically acceptable?

Mary swam five more laps than Joan swam.

response: acceptable

instruction: Is the next sentence syntactically and semantically acceptable?

Ellen said to Helen that melons were selling well.

response:
acceptable