This chapter discusses the growing effect of loanwords on the word formation of Titsch and Töitschu, two Walser German varieties spoken in the Aosta Valley in the Northwest of Italy, in Gressoney and Issime, respectively. Even if both communities of speakers are surrounded by a Romance-speaking area, the two varieties display strikingly different results due to distinct histories of language contact. The chapter considers the case of verb borrowing and the collapse of the stratal condition constraining certain word formation rules to apply only to non-native bases in Töitschu, the development in both varieties of a productive class of semelfactive action nominals not occurring in Modern Standard German and the emergence in Töitschu of phrasal verbs linked to the more general syntactic remodelling sustained by this variety. The phenomena considered show how contact has resulted in the extensive borrowing of patterns of a growing complexity, in direct dependence of the intensity of the contact with the surrounding Romance varieties.