The number of foreign languages spoken in Germany is rising, and as a result German is increasingly being learned as a second language (L2). This is a challenge for many secondary-school students, especially those who have learning disabilities (LD) and behavioral difficulties, which are often accompanied by reduced motivation to learn, in this case to learn a new language. Vocabulary is foundational for language development and literacy. In the current study, a combined storytelling intervention was used to help students build their expressive vocabulary in a short time. Specifically, five secondary-school students learning German as a second language -- some of whom also had social-emotional difficulties -- took part in a storytelling-based intervention three times a week for six weeks as part of a single-case study. The results indicate the intervention is an effective way to teach vocabulary, with stable data in the target sample. In addition, social validity questionnaires showed positive intervention ratings. Altogether, the storytelling intervention was found to be an advantageous way to support students with different needs in L2 learning.