By: Ellen Kester, Ph.D., CCC-SLP and Alejandro Brice, Ph.D., CCC-SLP
The Regional Education Service Centers in the State of Texas are providing a series of presentations for speech-language pathologists in school districts throughout Texas focusing on language differences versus language disorders.  The first two parts of the four-part series have been completed.  The address typical speech development in bilinguals and typical language development in bilinguals.
 
One of the charts that was very popular in the first presentation was the Venn diagram of the sounds of English and Spanish.  The sounds in the middle of the Venn diagram exist in both English and Spanish, while those on the sides are unique to one language or the other.  Overlapping sounds tend to be earlier developing sounds.  This framework can be applied to any pair of languages.  Information about the similarities and differences of the phonetic inventories of two languages can be readily found on the internet.  You will find multiple sources so look for consistency between sources before you use the information to make clinical judgments.
 
To use the charts, look for the errors that your bilingual client/student makes.  If you only identify errors on sounds that do not exist in the speaker’s native language, you are likely looking at a difference in speech production rather than a disorder.
 
It is also critically important to evaluate sound production in the native language, even if this has to be done informally.  Research the sounds of the speaker’s native language and come up with a list of words for you or your interpreter to present.  If your client does not make errors in their native language but they do in English on sounds that do not exist in their native language, they are likely experiencing language differences.  If the client is making errors on sounds that exist in both languages that are not typical in development, they are likely experiencing atypical errors in sound production.