"Self-directed speech"--the audible or partially whispered self-talk that children engage in during their daily activities, was proposed by Vygotsky to have a mediating role in the emerging self-regulatory behaviour of young children. Studies with correlational findings tend to lend support to this hypothesis but fail to delineate the real-time temporal interactions between self-directed speech and self-regulatory behaviour. The authors propose the use of lag sequential analysis and "t-pattern analysis" as useful and complementary methods for detecting significantly recurring patterns of co-occurrence of self-directed speech and non-verbal behaviour (that is either self-regulatory or shows a failure of self-regulation). Furthermore, it is argued that the analysis of these co-occurrences is required to establish the functions of self-directed speech, and to determine in what ways these might be self-regulatory. Illustrative analyses are presented of data from a study comparing the patterns of self-directed speech use during a planning task in typically developing children and matched peers with Specific Language Impairment. The results obtained from t-pattern analysis reveal qualitative differences between these two groups of children, in their use of self-directed speech, which were not detected by the other two methods. Implications of examining recurring temporal patterns in behaviour for research investigating aspects of development, particularly self-regulation, are discussed.