Is the following sentence linguistically acceptable?
What you heard was an explosion.

acceptable

Is the following sentence linguistically acceptable?
Angus is not leaving.

acceptable

Is the following sentence linguistically acceptable?
Sodium is a little too peppy for me to want to try mixing it and water in a teacup.

acceptable

Is the following sentence linguistically acceptable?
They believe Charles Darwin's theory of evolution is just a scientific theory.
acceptable