interface Pointlike { x: number; y: number; } interface Named { name: string; } function logPoint(point: Pointlike) { console.log("x = " + point.x + ", y = " + point.y); } function logName(x: Named) { console.log("Hello, " + x.name); } const obj = { x: 0, y: 0, name: "Origin", }; logPoint(obj); logName(obj); Try