Codeswitching is the linguistic phenomenon that refers to the alternation between two languages within the same utterance. Codeswitches may occur in between within a sentence or sentence fragment (intrasentential codeswitching) or between sentences (intersentential codeswitching). Bilinguals utilize a cognitive control mechanism that allows them to switch from one language to the other, with seemingly effortless ease. However, it is often believed that codeswitching incurs a switch cost in production and comprehension. If this were true, why would bilinguals codeswitch? The present study aims to answer the question: is codeswitching costly? By using eye-tracking tmethodology, readers’ eye movements were recorded while they read unilingual and codeswitched sentences. The analyses consisted of comparing the time taken to read different unilingual and codeswitched sentences. Longer reading times are normally associated with some type of processing cost. The results show that bilinguals read codeswitched sentences at around the same speed as unilingual sentences. This observation reveals that codeswitching is not costly for bilinguals for whom codeswitching is part of their linguistic repertoire.
