This study investigates the roles of just, a lexical item that is among the most frequent in distinguishing academic speech data from roughly comparable written data, in the Michigan Corpus of Academic Spoken English (MICASE). Concordance analysis showed that just frequently co-occurs with metadiscourse and hedging; a closer functional analysis in selected speech events showed that these collocations were often used with a mitigating function. Minimizers, including limiters as well as mitigators, together made up the overwhelming majority of tokens, while the more frequently taught “temporal” function was much less common, especially in the more formal speech events. Analysis of the phonetic forms of the various functions of just suggest that the mitigating use involves a very reduced token, whereas other functions such as that paraphrasable by “exactly” are more likely to use a full vowel and to be stressed. This suggests that materials for teaching non-native speakers academic English would benefit from greater attention to issues of phonetic detail, as an inappropriately stressed mitigating just may be misinterpreted by native listeners.