Given the common ancestry of Dutch and Afrikaans, it is not surprising that they use similar periphrastic constructions to express progressive meaning: aan het (Dutch) and aan die/’t (Afrikaans) lit. ‘at the’; bezig met/(om) te (Dutch) lit. ‘busy with/to’ and besig om te lit. ‘busy to’ (Afrikaans); and so-called cardinal posture verb constructions (zitten/sit ‘sit’, staan ‘stand’, liggen/lê ‘lie’ and lopen/loop ‘walk’), CPV te (‘to’ Dutch) and CPV en (‘and’ Afrikaans). However, these cognate constructions have grammaticalized to different extents. To assess the exact nature of these differences, we analyzed the constructions with respect to overall frequency, collocational range, and transitivity (compatibility with transitive predicates and passivizability). We used two corpora that are equal in size (both about 57 million words) and contain roughly the same types of written text. It turns out that the use of periphrastic progressives is generally more widespread in Afrikaans than in Dutch. As far as grammaticalization is concerned, we found that the Afrikaans aan die- and CPV-constructions, as well as the Dutch bezig- and CPV-constructions, are semantically restricted. In addition, only the Afrikaans besig- and CPV en-constructions allow passivization, which is remarkable for such periphrastic expressions.