Speech production is a highly creative process, yet there are a number of subtle factors which influence how we speak in context. This study combines previous work on use of optional ‘that’ in sentence-complement structures with research into accommodation theory and Foreigner Talk by looking at differences in use of ‘that’ in the context of interlocutor nativity. Sentence-complement structures, such as “I believe you...”, can be ambiguous, often results in misinterpretation on the part of the listener (Garden-Pathing) which can be avoided by use of option ‘that’. This study uses a mixed design to look at the effects of main and embedded subject on use of ‘that’ in conversation with native versus nonnative English speakers, in an effort to support previous evidence of the effects of social factors on ‘that’ production (Ferreira & Hudson, 2010). Unfortunately, no previous model for use of optional ‘that’ was supported by the findings that ‘that’ is used more frequently with an embedded subject of ‘you’. However, ‘that’ was shown to be used more frequently in discourse with nonnative speakers, showing that native speakers are sensitive to nonnative speakers’ potentially greater need for disambiguation.