The progressive "marker" is a complex entity in Afrikaans (cf. Dutch and German): aan die + bare infinitive + wees (literally: [on the V be]). Aan die + V is a tight construction. It may scramble to the left edge of the verbal cluster, so that grammatical particles may interrupt the progresssive construction. However, if wees is finite, it has to undergo V2 in main clauses (and optionally so in subordinate clauses). The same is true for the besig wees om te (busy be INF.CONJ to) construction, and also for the hou aan ('carry on').