Used to attract someone's attention.
A short distance; hailing distance.
A long, loud call used to attract attention when at a distance, mainly done in the Australian bush.
To make such a call.
An exclamation used to express pleasant or unpleasant mild surprise, indignation, or impatience.
Reason.
For which cause, reason, or purpose.
The cause, reason, or purpose for which.
Introducing a noun or other phrase.
Introducing a verb phrase (bare infinitive clause).
Introducing a complete question.
With a negative, used rhetorically to make a suggestion.