This article focuses on the acquisition of German verb inflection by native speakers of Thai, an isolated language which has no concept of inflection at all. The acquisition process of German verb morphology is analyzed based on all the verb inflectional affixes found in the corpus consisting of spontaneous utterances in Standard German produced by16 female immigrants living in German-speaking Switzerland. It aims to find out a systematic acquisition order of verb inflectional morphemes and the explanation to this sequence, especially to answer the following four questions: 1) What is the acquisition order of verb inflectional morphemes found in this group of informants 2) Are there any differences between the acquisition of finite and that of non-finite verbs? 3) Are there any differences in the verb morphology acquisition of different types of verbs? 4) Does the acquisition of verb inflection by these informants share more similiarities with the instructed or with the natural acquisition of German as a second language?