Perceiving Speaker’s Certainty: The Interaction Among Subjectivity of Statement, Evidential Markers, and Evidence Strength

Evidentiality is a linguistic category whose primary meaning is the source of information, which is generally divided into firsthand perception, hearsay, and inference. Evidential markers are the linguistic devices that indicate information sources. While considerable studies have revealed that evidential markers have an effect on the perceived speaker's certainty, no comparison on such an effect has been carried out in subjective and objective sentences. Moreover, with evidential markers and evidence strength both influencing the speaker's certainty, their relationship when used in collocation has not been investigated. This article examined, in two experiments, the intertwinement of inferential markers, subjectivity, and evidence strength in affecting the perceived speaker's certainty in Chinese. Participants were asked to judge the perceived speaker's certainty in sentences with and without inferential markers and also in sentences with different degrees of evidence strength in subjective and objective conditions. Our results revealed that (i) subjective evaluations are conceived with a lower degree of the speaker's certainty than objective sentences; (ii) Chinese evidential markers change the perceived speaker's certainty in subjective and objective sentences; and (iii) evidence strength plays a role in subjective evaluations but not in objective sentences. Our results show the participants reasoning the subjective evaluation themselves based on the evidence, but adopting the speaker's evaluation on the objective situations. Overall, our study supported that inferential markers significantly lowered the perceived speaker's certainty, and reported the different effects of evidence strength in objective sentences and subjective evaluations.