instruction: Is the next sentence syntactically and semantically acceptable?

Which problem does the sooner that you solve, the more easily you'll satisfy the folks up at corporate headquarters?

response: unacceptable

instruction: Is the next sentence syntactically and semantically acceptable?

Sally might be pregnant, and I believe that Sheila definitely is pregnant.

response: acceptable

instruction: Is the next sentence syntactically and semantically acceptable?

She kept not seeing him.

response: acceptable

instruction: Is the next sentence syntactically and semantically acceptable?

What happened was they went home.

response:
acceptable