Inquiry has displayed that prompting learners to elaborate on the fitness of form-meaning links can be an efficient vocabulary learning exercise (Deconinck, Boers & Eyckmans, 2017). This article wants to elucidate the mental processes that occur during this specific elaborative task by exploring the impact of individual learner variables pertaining to former linguistic knowledge and a number of word-specific features. To this end fifty Dutch-speaking EFL learners rated the congruency they perceived between the form and meaning of 24 English words on a 6-point Likert scale. The motivation of their scores was evoked by means of a think-aloud protocol, the transcriptions of which were explored with regard to the type of elaborations made. Vocabulary size tests and a language background questionnaire supplied additional information about the learners. The article distinguished five types of elaborations: cross-lexical associations, sound-symbolic associations, word-form comparisons, morphological associations, and idiosyncratic associations. The data also disclose that the individual learner variables and word-specific features explored in the present inquiry have an influence on the number of elaborations made by the learners. Pedagogical implications and suggestions for further inquiry are debated.