Why do bilingual speakers code-switch (mix their two languages)? Among the several theories that attempt to explain this natural and ubiquitous phenomenon, the Triggering Hypothesis relates code-switching to the presence of lexical triggers, specifically cognates and proper names, adjacent to the switch point. We provide a fuller, more nuanced and refined exploration of the triggering hypothesis, based on five large datasets in three language pairs, reflecting both spoken and written bilingual interactions. Our results show that words that are assumed to reside in a mental lexicon shared by both languages indeed trigger code-switching; that the tendency to switch depends on the distance of the trigger from the switch point; and on whether the trigger precedes or succeeds the switch; but not on the etymology of the trigger words. We thus provide strong, robust, evidence-based confirmation to several hypotheses on the relationships between lexical triggers and code-switching.

翻译：为何双语者会进行语码转换（混合使用两种语言）？在试图解释这一自然且普遍现象的若干理论中，触发假说将语码转换与词汇触发因素（特别是同源词和专有名词）在转换点附近的存在相关联。我们基于三个语言对的五个大型数据集（涵盖口语和书面双语互动）对该触发假说进行了更全面、更细致且更深入的探索。结果表明，被认为存在于两种语言共享心理词汇中的词汇确实会触发语码转换；转换倾向取决于触发因素与转换点的距离，以及触发因素出现在转换点之前还是之后，但不受触发词语源的影响。因此，我们为关于词汇触发因素与语码转换之间关系的若干假说提供了坚实、稳健且基于证据的确认。