instruction: Is the next sentence syntactically and semantically acceptable?

I inquired if we could leave early.

response: acceptable

instruction: Is the next sentence syntactically and semantically acceptable?

I succeeded in convincing, even though John had failed to persuade, Mary not to leave.

response: acceptable

instruction: Is the next sentence syntactically and semantically acceptable?

She wanted to can leave

response: unacceptable

instruction: Is the next sentence syntactically and semantically acceptable?

John wants to find a solution better than Christine's.

response:
acceptable