Cain killed Abel... Is that what you are looking for?
A before the climax move the story forward
He demonstrated the mathematical equation by solving it on the board.
The infinitive in this sentence is <em>to see (if it is done).
</em>It is used as an adverb in this sentence. Check the turkey. Why? To see if it is done.
<em />When you are answering questions such as when, where, why, it means that you are dealing with adverbs.