Transitivity system 2)mental process: --process of sensing,clauses of thinking, feeling and perceiving. In mental process,firstly there is always one participant who is human;this is the one that "senses"--feels,thinks or perceives. Secondly,the other main element which is felt, thought or perceived may be not only a "Thing", but also a "Fact"Transitivity system 2) mental process: --process of sensing, clauses of thinking, feeling and perceiving. In mental process, firstly there is always one participant who is human; this is the one that "senses"--feels, thinks or perceives. Secondly, the other main element which is felt, thought or perceived may be not only a "Thing", but also a "Fact