The continued underperformance of many L2 students at primary, secondary and tertiary level is a cause for grave concern in South Africa. In an attempt to better understand the cognitivelinguistic conditions and processes that underlie academic performance and underperformance, this study looks at the problem of differential academic performance by focussing on the inferential ability of undergraduate L2 students during the reading of expository texts. The study works within a constructivist theory of reading, where the successful understanding of a text is seen to involve the construction of a mental representation of what the text is about. Inferencing plays an important role in constructing meaning during reading because it enables the reader to link incoming information with already given information, and it enables the reader to construct a mental representation of the meaning of a text by converting the linear input into a hierarchical mental representation of interrelated information. The main finding showed that the ability to make inferences during the reading of expository texts was strongly related to academic performance: the more inferences students made during the reading of expository texts, the better they performed academically. This relationship held across the making of various inferences, such as anaphoric inferences, vocabulary inferences, inferences about various semantic relations, and thematic inferences. In particular, the ability to make anaphoric, contrastive and causal inferences emerged as the strongest predictors of academic performance. The study provides strong empirical evidence that the ability to make inferences during reading enables a reader to construct meaning and thereby also to acquire new knowledge. Reading is not only a tool for independently accessing information in an information-driven society, it is fundamentally a tool for constructing meaning. Reading and inferencing are not additional tools that students need to master in the learning context- they constitute the very process whereby learning occurs. / Linguistics and Modern Languages / D.Litt. et Phil. (Linguistics)