Abstract
Phonological short-term memory (PSTM) capacity is the ability to retain verbal information briefly (Archibald
& Gathercole, 2006). Since PSTM facilitates the storage of verbal material, one expects a positive relationship between PSTM
and several aspects of second language (L2) learning. Some studies have found a relationship between PSTM and oral production
skills, such as fluency (e.g., O’Brien et al., 2006). This paper reports on the results
of a study that looked at the inter-relations between complexity, accuracy, and fluency (CAF), and between these dimensions and
PSTM. One hundred and thirty-five L2 learners of Spanish participated in the study. Results showed that performance in one L2
speech dimension did not have a negative impact on performance in another dimension, but that as complexity increased or
decreased, there was a better chance of fluency than accuracy also increasing or decreasing. PSTM capacity was related to
complexity and fluency, but not to accuracy. These results were interpreted as lending some support to Skehan’s Trade-off
Hypothesis (Skehan, 2009).