Is the following sentence linguistically acceptable?
If John can speak French fluently which we all know he can we will have no problems.

acceptable

Is the following sentence linguistically acceptable?
The teacher who that the principal would fire was expected by the reporters is a crusty old jerk.

unacceptable

Is the following sentence linguistically acceptable?
The person whom they intended to speak with agreed to reimburse us.

acceptable

Is the following sentence linguistically acceptable?
I don't have any potatoes.
acceptable