The ideational function (sometimes also referred to as experiential function) is realized by the transitivity system of language. The word transitivity is not used in the same sense as it is in traditional grammar where transitivity is a quality of a verb which can take an object. Here it is a type of linguistic process which represents what exists and what is going on around us and inside us.

　 The reality is categorized into DOING, BEING (the physical world), and SENSING (the world of consciousness). The three main linguistic processes representing these are termed material processes, relational processes, and mental processes.

　　Material processes
　　Relational processes
　　Mental processes
　　Verbal processes
　　Behavioral processes
　　Existential processes