Peer-reviewed research
Using uh and um in spontaneous speaking
Herbert H. Clark and Jean E. Fox Tree, Cognition, 2002 · DOI 10.1016/S0010-0277(02)00017-3
Read the originalRead on October 16, 2026
- What it is
- A study of spontaneous speech from several large corpora that proposes uh and um are words speakers use to announce a delay in speaking, a short one for uh and a longer one for um. The paper is by two psycholinguists, Herbert Clark of Stanford and Jean Fox Tree of the University of California, Santa Cruz.
- How much weight it carries
- Peer-reviewed in the journal Cognition and widely cited. The argument rests on corpus analysis of natural conversation rather than on a single experiment, so it describes patterns rather than proving intent. The url is an open PDF copy of the article, not the publisher's page.
Facts taken from this source
- Clark and Fox Tree proposed that speakers use uh and um to announce a delay in speaking: a minor one they expect after uh, and a major one after um.
“speakers use uh and um to announce that they are initiating what they expect to be a minor (uh), or major (um), delay in speaking” (Abstract)