Hard describes something that resists pressure or force. A rock is hard because you can't easily dent or scratch it with your finger. A math problem is hard when it takes real effort and concentration to solve. Hard work means putting in serious, sustained effort over time.

The opposite of hard is soft when talking about physical objects, or easy when talking about difficulty. A hard cushion doesn't give much when you sit on it. A hard decision requires careful thought because the right choice isn't obvious.

When someone works hard, they're giving their full effort and attention. Hard-working students push themselves to understand the material deeply, going beyond the minimum required.

The word appears in many expressions. Hard times means periods of difficulty or struggle. Something hard and fast is a strict rule with no exceptions. To be hard on someone means to judge or criticize them severely. When you try hard, you're giving your maximum effort.

Physical hardness matters too. Diamond is the hardest natural substance, which is why it can cut through almost anything else. Understanding both meanings helps you recognize whether someone's talking about effort, difficulty, or physical properties.