Work 可當不可數和可數名詞用，兩者的意思有很大的不同。
Work 用作不可數名詞時意為「工作；勞動」，其前不可有表示單數的不定冠詞 a，也不可加 s 變成複數型。至於指特定職業的「工作」，或者是指經常性、不情願或很難做的「工作」，英文叫做 job，是個可數名詞。例如：
- My mom has got so much work to do every day. (我媽媽每天都有一大堆工作要做)
- We’ve got exams next week. I’ve got a lot of work to do. I’m not going out tonight. (我們下週要考試。現在我有許多作業要做/許多書要唸。今晚我不外出了)
- He’s applied for a job with a software company. (他已應徵一家軟體公司的工作) (正)
He’s applied for a work with a software company. (誤) - Mary spent the afternoon doing a lot of jobs around the house, like cleaning, washing clothes, gardening, and so on. (瑪麗下午在家裡做了許多雜務，如清掃、洗衣、園藝等等) (正)
Mary spent the afternoon doing a lot of works … (誤)
Work 用作不可數名詞時還有一個相當常用的意思，那就是「工作場所，工作地點」。例如：
- Do you have far to go to work each day? (你每天上班路途遠不遠？) － Far 在此當名詞 (不可數) 用，意為「遠方；遠處」。再舉一例：I haven’t far to go now. (現在我不必走很遠了)。
- Thousands of people are seriously injured at work every year. (每年都有數以千計的人在工作中受重傷)
- My father was out of work at the time. (我父親當時失業)
- When does Kevin leave for work? (凱文什麼時候出門去上班？)
Work 用作可數名詞時意為「(尤指繪畫、書籍、音樂或雕刻) 作品，著作」。例如：
- I bought her the complete works of Oscar Wilde for her birthday. (我買了王爾德全集當作她的生日禮物)
- The gallery has a lot of works by Picasso as well as other modern painters. (這座美術館有許多畢卡索的作品以及其他現代畫家的作品)
- This novel is his latest work. (這本小說是他最新的作品)
複數型 works 當可數名詞用 (單複數同形)，意為「工廠 (factory)」，如 an ironworks (一家鐵工廠)，two ironworks (兩家鐵工廠)；a steelworks (一家鋼廠)，two steelworks (兩家鋼廠)。注意：Ironworks 和 steelworks 原本寫成 iron works 和 steel works，但現在都拼成一個字。