The Sayer can be anything that puts out a signal, like 'the notice' or 'my watch'; c.f. 'the light' in 'the light says stop', 'the guidebook' in 'the guidebook tells you where everything is'. Such entities could not figure naturally as Senser in a mental process: 'my watch thinks it’s half past ten' is decidedly incongrous. But 'my watch says it’s half past ten' calls for no comment at all; a Sayer can just as readily be 'it' as 'he' or 'she'. For this reason verbal processes might more appropriately be called ʻsymbolicʼ processes.
- Halliday (1985), Pag. 129-130