This dissertation addresses the acquisition of Sign Language of the Netherlands (Nederlandse Gebarentaal, NGT) in adult learners with a spoken language background. These learners acquire a new language in a new modality, the visual-spatial modality, which differs from the oral-auditory modality of their native language, Dutch. One of the modality-specific linguistic features attested in signed languages, but not in spoken languages, is the use of space to express grammatical and topographical relations. Our knowledge of the acquisition of linguistic devices related to the use of space (e.g., pointing signs, agreement verbs, classifier predicates and signs marked for location), and of appropriate pedagogical practices to teach these structures, is very limited. This thesis contributes to filling this gap by improving our understanding of processes underlying the acquisition of these devices in L2-learners of NGT, and by investigating whether certain pedagogical practices, which have been shown to be effective for L2-learners of a spoken language, would facilitate the acquisition of these devices. Four studies were carried out. The first three studies, in which we analyze (semi-)natural and elicited production data of novel NGT learners who were followed longitudinally, serve as basis for the fourth study, in which we investigate whether learners benefit from pedagogical interventions aimed at focusing their attention on the form-meaning mappings of one of the devices under investigation, agreement verb forms. This dissertation provides valuable information for practitioners in the field, and adds to our understanding of the intersecting fields of sign language linguistics, second language acquisition and pedagogy, as well as gesture studies.