This is a case study that focuses on the oral proficiency in English manifested by the 4-year-old sonof the author. He speaks Swedish as his L1 like his both parents but has been exposed to Englishsince he was one year old from using a tablet. The child’s spoken production was recorded andtranscribed with a focus on the plural-forms and the genitive. An important field that this case studyis motivated by is how child language development may be connected to the concept of innatism,that language is based on innate principles (Lightbown & Spada, 2013:20) as it has been found that anumber of languages are acquired according to predictable patterns and processes (Moskowitz,1994:621-627) such as a the u-shaped learning process and over-generalization which has beenfound when investigating both L1 and L2 acquisition (Abrahamsson, 2013:663). The aim of thisstudy is to find possible similarities within the learning process: whether L2 acquisition follows thesame developmental patterns as in L1 acquisition by analyzing the recordings mainly targeting theplural and the genitive morphemes produced by a 4-year-old L2 speaker of English. Findings in thisresearch revealed that the child demonstrated a similar developmental pattern in the form of theu-shaped learning process (Abrahamsson, 2013:663).