The purpose of the current study was to examine into which groups of meaning the derivational morpheme – skap can be grouped in Swedish. 340 Swedish words formed with – skap were collected from SAOL and grouped into different groups of meaning based on 1) their meaning, and 2) their part(s) of speech. For example, words that express a state of being, such as galenskap (madness) and havandeskap (pregnancy) were placed into one group. Words that refer to a work or a title, such as ridderskap (knighthood), presidentskap (presidency), and författarskap (authorship), were grouped together in another group. Using this method, the results show that the gathered 340 words could be divided into 11 different groups expressing 1) state of being, 2) environment, 3) belonging, 4) kinship, 5) work, title, office, 6) tools, 7) sport events, 8) economy and finances, 9) information and forms of knowing, 10) mischief, and 11) remaining words. This study also aimed at examining to what extent an intervention focusing on word formation, and derivational morphemes in particular, affect Swedish upper-secondary school students’ metamorphological awareness. The intervention was a quasi-experimental study in which 58 students participated. The participants were first given a pre-test to determine whether they had a high or low metamorphological awareness. This was determined by their ability to define five different Swedish derivational morphemes. Afterwards, they participated in an intervention in the form of a lesson where they were taught basic word formation with the focus on derivational morphemes, which was succeeded by a post-test, which examined the effect the intervention had had on the participants’ metamorphological awareness. The post-test was identical to the pre-test, with the exception of five additional words formed with – skap, with the purpose to compare the students’ definitions to the groups of meaning presented in the first part of this study. The results show that the intervention had a great effect on the participants’ metamorphological awareness. For example, in the pre-test, most of the participants had either one or two correct definitions, but in the post-test, the majority of the participants had either four or five correct definitions, which indicate an increase of metamorphological awareness.