Which tool is primarily used to shape nails in manicures?

The tool that is primarily used to shape nails in manicures is the nail file. A nail file is designed specifically for smoothing and shaping the free edge of the nail. It comes in various materials and grits, allowing for a customizable approach to nail shaping. The fine textures of nail files enable precision in contouring the nails, making them appear polished and well-groomed.

Other tools, while useful in a manicure, serve different purposes. Nail scissors are primarily used for cutting excess nail or skin but are not ideal for shaping. Nail buffers are designed to smooth and shine the surface of nails rather than shape them. Nail clippers are mainly used to shorten the nails or trim them down and do not provide the nuanced shaping that a file does. Thus, the nail file stands out as the essential tool specifically used for shaping nails during manicures.