Studies on vocabulary learning have provided valuable knowledge of what it means to know a word and how people learn. Few studies have focused on what students’ understanding of word knowledge and vocabulary acquisition can contribute with in a language-learning context. Considering the vital importance of vocabulary in language learning, this study explores students’ experiences of word knowledge and vocabulary learning with a point of departure in phenomenographic research. By interviewing a group of Swedish secondary school students about their understanding of word knowledge and what strategies they employ to learn new words in English, categories of description emerged showing that although the majority of the students reported that they perceive word knowledge as contextual, they primarily employ decontextualised strategies when studying vocabulary. This discrepancy seems to be closely connected to how vocabulary is tested and assessed in school.