Background of The Study

B : Well, hmm, let's see... Tomorrow's Tuesday, right? I told Harry I'd have lunch with him. And I told him so long ago that I'd feel bad canceling. Maybe another time, okay? (adapted from Finegan, 1994, p. 351 as cited in Rose, 1998, p. 17)

Along with that, Hayamizu (2002, par. 4) calls this function as an affective and cognitive function because for achieving smooth dialogue by sharing mental states among interlocutors, a speaker uses fillers to express mental state such as mitigation to seek an expression appropriate for a listener. On the other hand, a listener interprets fillers as indicators for inferring speaker's mental and thinking states.

For example:

A : May I borrow your car on Saturday night? B : Err...

A: Or maybe I can ask Philip. (as cited in Rose, 1998, p.18)

In this case, B's err... is a complete act signaling objection to A's request. Thus, A offers an escape to maintain harmony (Rose, 1998, p.18).

As mitigating devices, fillers also function as a solidarity marker or politeness device. According to Baalen (2001, par.6) fillers are useful to express opinions but to soften them in the process. She also says that protecting face needs is an important function of fillers because face needs are the need to feel acknowledged and liked (positive face needs) and the need to have one's personal space respected (negative face needs). Koide (1983) and Cook (1993, as cited in Fujita, 2002, par.1) also give the same opinion about the functions of fillers which are increasing the politeness of one's speech and aligning a speaker and a listener in face-to-face interaction. In addition, Knapp and Vangelisti (2005, p.254) have 

found that fillers increase when the speaker is trying to save the relationship or terminate it. So, here fillers can function as mitigating or politeness devices.

For example:

"You have some... err... jelly on your chin..." (adapted from Rose, 1998, pp.2-3)

In that statement, it seems unlikely that the speaker is having difficulty lexicalizing such a common word as jelly. Rather, it appears that s/he is trying to avoid embarrassing her/his interlocutor.