A study on the errors of spoken English made by the vendors at Kuta Beach Bali

English is the mostly used language by vendors in Bali to offer their merchandise to tourist. However, the investigator found that many vendors, especially at Kuta Beach, in some cases, were still influenced by their mother tongue -in this case Bahasa Indonesia- in expressing their spoken English. This condition made those vendors to produce wrong sentences which sometimes failed a trading. The situation above led the investigator to conduct a study on analyzing the vendors' errors in English spoken sentences. In conducting this study, the investigator used a small tape recorder and a notebook. With the help of a French-tourist, she recorded the vendors' English conversations without being known by the vendors themselves in order to get the most natural data. After the investigator transcribed the data, identified, analyzed, classified them based on the types of errors and counted the errors as well as the reasons why the vendors made those errors, she ranked them according to the frequency of their occurrences and found that the most errors that the vendors made were omission errors (0.65%) followed by misformation errors (0.21%), misordering errors (0.08%} and addition errors (0.06%}. In the prediction of the causes of errors it was found that the errors appeared were not only because of the mother tongue influence (interlingual interference) but also because of the reflection of general characteristics of rule learning such as faulty generalization, incomplete application of rules, and failure to learn conditions under which rules apply (intralingual interference) as well. Being a case study, this research does not offer any generalization out of its findings. Nevertheless, the findings do inform us that the different system of Indonesian and English rules made the vendors face confusion in producing correct spoken English sentences. Consequently, this study is expected to give information (or feedback) to the vendors to improve their spoken English language