Input/output switch in bilingual code switching

Chinese-English bilinguals were asked to read a passage with spontaneous bilingual code switchings, compared with a unilingual Chinese translation of the passage, a unilingual English translation, a translation with random switchings, and a translation with only nouns switched into English. There was no difference between the reading speed for the passage with natural switchings and the unilingual Chinese passage, thus questioning the need to postulate a bilingual imput/output switch. The speed for reading passages with artificial switchings was slower. In a translation task, the naturally switched items required less time in Chinese-to-English translations compared with English-to-Chinese translations. This indicates that in natural code switchings, the English lexical items produced were more available, even though English is generally the weaker language.