As students learn to write their scientific knowledge on specific topics can develop. In a study of four university students, we show how students progress from mapping concepts to linguistic expressions more literally to an increasing use of grammatical metaphor. One such case is the nominalization of events and actions, where a semantic content typical of verbs is mapped onto nouns. Despite this aspect typical of scientific texts, their writing differs from that of scientists. Whereas the latter speak more generally and systemically, students do so more specifically and instantially.