Metal is the material, such as iron or steel, and also a style of loud rock music. Mettle is courage and determination. You prove your mettle when things get hard, and you build a bridge from metal.
The core difference
Metal is a physical material or a music genre, while mettle is courage and strength of character.
- metal — a hard, shiny material such as iron, or a rock music genre: The bridge was built from steel, a strong and durable metal.
- mettle — courage and determination when things are difficult: The rookie proved her mettle during the final, high-pressure match.
How to tell them apart
The two words have the same origin: mettle began as a figurative spelling of metal in the 1500s, and for a while they were interchangeable. They then split into separate words with separate meanings, which is why they are pronounced the same and still confuse people.
A handy trick is that mettle is a quality of a person, so you never use it for an object. If you could touch it, it is metal. If it describes how someone copes under pressure, as in test your mettle or show your mettle, it is mettle.
