Tim Bowen has been working hard to bring you this article.

Hard functions most commonly as an adjective but it can also be used as an adverb and, in both forms, is used in a range of idioms.  

Apart from its more common adjectival meanings, hard can be used to mean ‘strong and not easily frightened’, as in ‘He likes to pretend he’s hard but he’s really soft underneath’. It can also be used to describe water. Hard water is water that does not mix easily with soap because it contains a lot of minerals. Hard facts are certain and can be proved, as can hard evidence. If you are hard at something such as work, you are engaged in it busily, but if you are hard on someone, you are unpleasant to them and criticize them a lot. If something is hard on something else, it causes damage to it, as in ‘Aerobics is quite hard on the knees’.

As an adverb, hard means ‘using a lot of effort’. In this sense, apart from its use with verbs such as work, fight and try, it can also be used with verbs like look, listen and think, as in ‘I had to think hard before coming up with the right answer’, meaning ‘carefully and with your full attention’. If you feel hard done by, you feel as if you have been treated unfairly, and if you are hit hard by something, you are very badly affected by it, as in ‘Small firms in particular have been hit hard by the recession’. In this last expression, the word order can be reversed without changing the meaning, as in ‘This region has also been hard hit’. Finally, if you take something hard, you are very upset by it, as in ‘He took it very hard when he lost his job’. If you are hard hearted you lack empathy and are harsh to someone, as in, ’It was very hard hearted of the teacher not to allow Jim to submit his homework late after he got ill.’