Halliday & Matthiessen (2004: 508):
Many of the ‘enhancing’ verbal group complexes are simply inappropriate in the passive; they characterise an approach or attitude to the process, and this is likely to apply to an Actor but not to a Goal — it does not make much sense to say she hastened to be reassured, or your word ventures to be doubted. Others, such as happen and tend, are impersonal and so are indifferent to the selection of voice; for example:
- The house happened to have been built facing the wrong way. …Since they are all metaphorical, in the sense that the verbal group is representing a circumstance and not some aspect of a process, the functional analysis provides only a partial interpretation; to get the full picture we would need to take account of the congruent form, eg by chance the house had been built facing the wrong way. There would be no change of rôle in the passive.