Andrea Schindler, Senior SLP from San Diego Unified, created this wonderful handout for determining when a sound pattern is due to a language difference (and not a disorder). She has listed the sounds in English and the sounds for several commonly spoken languages in San Diego Unified. This will help SLPs to determine whether or not a sound occurs in both languages. (Please note that this document only looks for the overlap in languages with English sounds. If a language includes other sounds, they are not listed.) For instance, as shown on the chart, Vietnamese does not include /θ/. If a child who speaks Vietnamese did not use /θ/, SLPs would respect that as a difference and treatment would not be warranted. However, if a child who speaks Vietnamese does not produce the /l/ sound, SLPs would treat the sound because it occurs in both Vietnamese and English.
In addition, there are two helpful websites in particular with similar information for other languages. Please visit Phonemic Inventories Across Languages at ASHA and The Speech Accent Archive. Dr. Sharynne McLeod's book, The International Guide to Speech Acquisition, is also highly recommended because it includes phonological information about 22 languages and 12 English dialects.