In bilinguals, code switching occurs when a word or a phrase from one language is replaced by a word or phrase from another language.
As a rule, the grammatical rule of the first language must be followed. In the following poem, even the rules of Vietnamese classic
« thơ lục bát » (six-wordsyllable verses alternating with eight wordsyllable verse). It is a is a typical case of
code switching in Vietnamese who frequently have to use another language besides Vietnamese (French, Chinese, and now English).
Code-switching can be distinguished from other language contact phenomena such as borrowing, pidgins and creoles (French patois
spoken in Haiti and Louisiana or similar languages). "While code-switching had previously been investigated as a matter of peripheral
importance within the more narrow tradition of research on bilingualism, it has now moved into a more general focus of interest for
sociolinguists, psycholinguists and general linguists." (Wikipedia).
During French colonial times, in Vietnam, before 1950, there was a related language phenomenon called "tiếng Tây bồi",
literally meaning 'French spoken by the servants ("boys"), or "Francais petit nègre" in French. A good example is another poem,
similar to this one in content, in which a woman said goodbye to her son who went to France with her husband:
..."Au revoir mon cher petit,
Maintenant fini maman"...
(Goodbye my dear little one
Now no more mommy).
Another example is the way a servant warned his master about a tiger's attack:
"Monsieur, le chat, grand beaucoup, lui manger vous, lui manger moi"
("Sir, the cat, very big, him eat you, him eat me", following Vietnamese syntax : "Ông ơi, con mèo, to lắm,
nó ăn ông, nó ăn tôi")
The Scribner-Bantam English dictionary (1979) defines pidgin as "an auxiliary language developed chiefly for commercial purpose, when
two or more people come into contact, based usually on one language, with a modified phonology and simplified morphology and vocabulary
and syntactic elements from the other languages." In the case of Tiếng Tây Bồi (French pidgin), it was based on
French with Vietnamese elements (syntactic element in the above examples) and used mostly between the uneducated servants ("boys")
and their French employers.
The following poem, circulated among the Vietnamese internet community nostalgic of its remote past, sounds very familiar but its
author(s) remain(s) anonymous. Perhaps it was created a long time ago, early in the 20th century, by several contributors in the oral
literature, during the French colonial period.