Halliday & Matthiessen (1999: 148):
The subtypes that have generally recognised in the grammar are (1) intransitive/transitive; (2) within intransitive, action/event; and within transitive, effectum/affectum. The first is the distinction between doings that involve only a doer (intransitive: John ran) and those that also involve something ‘done to’ (transitive: Mary threw the ball); realised respectively as Actor + Process, Actor + Process + Goal. The second is that between an intentional act by an animate (typically human) being (John ran) and an unintentional action or inanimate event (John fell; rain fell). […] The third is the distinction between a Goal that ‘exists’ prior to the doing of the deed (affectum: Mary threw the ball) and one that is brought into existence by the doing (effectum: Jack built a house).