Hard is both an adjective and an adverb. When it is an adverb, it means 'needing or using a lot of physical or mental effort'.

with effort; with great effort; with difficulty; to work hard; You must try harder. She tried her hardest not to show how disappointed she was.

19 июн. 2023 г. · It is the adverb “hard,” which is known as a “bare adverb.” It is not “hardly.” Examples: She worked hard to finish the project on time. When are 'hard' and 'hardly' used as adverbs? - Quora What is the adverb in the sentence, “Monish likes to do hard ... Другие результаты с сайта www.quora.com

(manner, archaic) Harshly, severely. (now rare) With difficulty. (degree) Barely, only just, almost not. ... Examples: “Trying to be “less bad” is hardly ...

6 дней назад · hard adverb [-er/-est only] (SEVERELY). in a severe or forceful way: They took the defeat hard.

The earliest known use of the adverb hard is in the Old English period (pre-1150). It is also recorded as an adjective from the Old English period (pre-1150).

11 июл. 2016 г. · “Hard” is an adverb which tells us that the person working is focused and doing a good job. Hardly Working indicates that the person is doing almost nothing!

The adverb 'hard' means with energy or force. It's raining hard. It's snowing hard.