Plenty 可當代名詞、名詞 (不可數) 和副詞用。
Plenty 用作代名詞時意為「大量，眾多」(通常指過多)。例如：
- A: How long will it take? (A：要花多久的時間？)
B: One hour should be plenty. (B：一小時應該足夠了) - A: Would you like some more coffee? (A：還想要些咖啡嗎？)
B: No thanks, I’ve had plenty. (B：不，謝謝，已經夠了」 - Don’t hurry – We’ve got plenty of time. (別急，我們有足夠的時間)
- Tom has always had plenty of money. (湯姆總是有很多錢)
- Plenty of teachers are always complaining about their salaries. (很多老師老是在抱怨他們的薪資)
- Peter has plenty of creepy stories to tell. (彼得有許多令人毛骨悚然的故事可講)
- There’s plenty (= plenty of things) to do in the office. (辦公室有很多事要做)
由上面的例句可知，plenty of 後面可接可數和不可數名詞。必須注意的是，plenty 沒有形容詞用法，不可直接放在名詞前面；換言之，名詞前面須使用 plenty of。例如：
- Tom has always had plenty of money. (湯姆總是有很多錢) (正)
Tom has always had plenty money. (誤) - I’ve got plenty of things to deal with. (我有許多事要處理) (正)
I’ve got plenty things to deal with. (誤)
Plenty 用作不可數名詞時意為「大量，豐富；充足，充裕」。例如：
- My brother and I have plenty in common. (我哥哥跟我有許多共通之處)
- This is a time of plenty. (這是一個富足的時期)
- Amy lives in plenty. (艾美生活富裕)
Plenty 用作副詞時意為「很多；足夠；相當；非常」，主要用於 plenty more、plenty big/large/strong/long etc. enough 等片語中。例如：
- There’s plenty more ice cream in the fridge. (冰箱裡還有很多冰淇淋)
- There are plenty more fish in the sea. (天涯何處無芳草)
- The restaurant is plenty big enough for eighty people. (這家餐廳足以容納 80 人)
- The rope was plenty long enough to reach the ground. (這條繩子夠長，足以伸到地面)
- Preparations for my sister’s wedding kept me plenty busy for a week. (我妹妹婚禮的準備工作讓我足足忙了一個禮拜)
- Paul talks plenty, but that’s all he does – talk. (保羅說了很多，但他所能做也就是說說而已)