This Year 3 Subordinating Conjunctions Prior Learning worksheet is fantastic resource to use to assess children's understanding of using because, that, when and if before moving onto subordinating conjunctions. With three varied fluency, one reasoning and two application questions, children are asked to identify the conjunctions in sentences, identify which sentences have used conjunctions correctly and rearrange given word cards to make a sentence which includes a conjunction.
Use this resource as a way to assess children's prior knowledge before moving on or alternatively, this could be used for those children who are less confident with conjunctions.