What does an uhm say about second language proficiency? This project investigates speaking fluency from the point of view of the second language speaker, and from the point of view of the listener. From the point of view of the speaker, disfluencies such as a pause or uhm may result from different kinds of problems. Speakers may say uhm because they do not know what to say. Speakers may also hesitate because they do not know how to say what they want to say. For second language speakers, the hesitations or disfluencies arising in this formulation stage of speech planning are more frequent than for native speakers, because they may have trouble selecting the correct word, or in making a grammatical sentence. In this project, we will investigate how disfluencies due to difficulties in formulating second language speech can be disentangled from other ( normal ) disfluencies. From the point of view of the listener, we will investigate how listeners perceive several types of disfluencies. We will ask raters to judge on fluency and investigate which aspects of speech they take into account when they are making their judgments. The results of these two viewpoints taken together will show which characteristics of productive and perceptual fluency overlap, and which characteristics tend to be unique for the chosen point of view.