This study is on the relation between developmental dyslexia and language comprehension. It provides novel evidence that children with dyslexia experience difficulties in the comprehension of sentences containing ambiguous pronouns, imperfective sentences, and sentences containing a universal quantifier. This evidence is used to formulate an hypothesis about the cognitive impairment underlying dyslexia. The result is the verbal Working Memory Deficit Hypothesis, according to which dyslexia is associated with a deficit affecting the verbal component of the Working Memory system. The study capitalizes on insights from both formal linguistics and developmental psychology. It is thus of interest to psychologists as well as to formal linguists.