Simplify the following text for a Grade 8 native English-speaking person.
Original: A Sergeant ( Sgt ) in the British Army wears three point-down chevrons on their sleeve and usually serves as a platoon or troop sergeant , or in a specialist position .
Simplified: A sergeant ( Sgt ) in the British Army wears three point-down chevrons , or `` checks '' on their sleeve . They usually serves as a platoon , troop , or group sergeant , or in a specialist position .