The ability to spell correctly is a fundamental skill for participating in society and engaging in professional work. In the German language, the capitalization of nouns and proper names presents major difficulties for both native and nonnative learners, since the definition of what is a noun varies according to one's linguistic perspective. In this paper, we hypothesize that learners use different cognitive strategies to identify nouns. To this end, we examine capitalization exercises from more than 30,000 users of an online spelling training platform. The cognitive strategies identified are syntactic, semantic, pragmatic, and morphological approaches. The strategies used by learners overlap widely but differ by individual and evolve with grade level. The results show that even though the pragmatic strategy is not taught systematically in schools, it is the most widespread and most successful strategy used by learners. We therefore suggest that highly granular learning process data can not only provide insights into learners' capabilities and enable the creation of individualized learning content but also inform curriculum development. [For the full proceedings, see ED615472.]