There is a large class of clauses in English which can be interpreted in this way, as consisting of a process with these particular participants – an obligatory Actor, and optionally also a Goal. This is the class that we shall refer to as a MATERIAL PROCESS.
- Halliday (1985), a pag.103

Material processes are processes of ʻdoingʼ. They express the notion that some entity ʻdoesʼ something – which may be done ʻtoʼ some other entity.
- Halliday (1985), a pag.103

Material processes are not necessarily concrete, physical events; they may be abstract doings and happenings.
- Halliday (1985), a pag.104

In a material process no participant is required to be human, and the distinction between conscious and non-conscious beings simply plays no part [...] In a material process, every participant is a THING: that is, it is a phenomenon of our experience, including of course our inner experience or imagination – some entity (person, creature, object, institution, or abstraction), or some process (action, event, quality, state or relation). Any of these ʻthingsʼ may also, of course, be the object of consciousness in a mental process [...].
- Halliday (1985), a pag.108