This chapter examines the question for singleton German and English fricative data from two cohorts of preschool children with Protracted Phonological Development (PPD). It outlines challenges for fricative acquisition and reviews previous research. The chapter addresses the issue of universal versus language-specific tendencies in the acquisition of fricatives by German-speaking and English-speaking children with PPD. The chapter suggests that substitutions tend to come from children’s phonetic inventories and the input language inventory/ies, suggesting that different inventories might result in different mismatch patterns. Caution is advised in interpretation, because the words evaluated were necessarily different between languages, and it cannot be taken for granted that all words are equivalent when comparing phonemes by position. Furthermore, the samples were relatively small, increasing the impact of individual differences, especially in samples of children with PPD, where heterogeneity may be higher than in typically developing (TD) samples.