Purpose: Realisation & WH– Probe

Halliday & Matthiessen (2014: 321-2):

Circumstantials of Purpose represent the purpose for which an action takes place – the intention behind it; they have the sense of ‘in order that’. They are typically expressed by a prepositional phrase with for or a complex preposition such as in the hope of, for the purpose of, for the sake of … The interrogative corresponding is what for?.