We beginnen met de les. (We begin with the lesson.)
beginnen takes "met / aan" (beginnen met / aan = to begin with). Example: We beginnen met de les. (We begin with the lesson.)
We beginnen met de les. — We begin with the lesson. The preposition met / aan is fixed, so it doesn't change with the sentence.
Fixed prepositions come up all over the A2 exam. The platform drills them in real exam tasks, AI-graded across all five DUO sections.