Algamus is not knowing where Algamus's favourite broom is. It is not being with other cleaning supplies, and Algamus knows where all cleaning supplies in the whole of Hogwarts is being, but Algamus is knowing where other broomses be. Maybe Algie's broom is with studentsies broomses?

The house elf appeared with a POP outside the broomshed. Algie's broom is being here! Algie can feel it!