核心畫面
Picture a small courtesy offered to someone: kind words on one hand, a glass of wine put on the table with no bill on the other. Both are the same gesture — something given, not owed. English keeps both under this one adjective, which is why a complimentary breakfast and complimentary remarks can look so unrelated and still be one word.
可以想成：一份小小的心意送到某人面前——一邊是好聽的話，一邊是一杯放上桌卻不算錢的酒。兩者其實是同一個動作：給出去，…更多收起
可以想成：一份小小的心意送到某人面前——一邊是好聽的話，一邊是一杯放上桌卻不算錢的酒。兩者其實是同一個動作：給出去，而不是欠人家的。英文把這兩面都收在同一個形容詞底下，所以 complimentary breakfast（免費早餐）和 complimentary remarks（讚美的話）看起來毫不相干，卻是同一個字。From the word’s history
Compliment came into English around the 1570s from Latin complementum via Italian and French, the notion being 'that which completes the obligations of politeness'; complimentary followed in the 1620s meaning 'conveying a compliment'. Compliment and complement are essentially the same word, their spellings separated only after about 1650. The 'free of charge' use is later, and by 1722 the word could describe a complimentary gift.
compliment 約在 1570 年代進入英文，源頭是拉丁文 complementum，經義大利文與法文而來，原本的想法是「把禮數補完的那個東西」；complimentary 在 1620 年代出現，意思是「傳達讚美的」。compliment 和 complement 本來就是同一個字，拼法要到 1650 年前後才分家。「免費贈送」是後來的用法，1722 年已可見 a complimentary gift 這樣的說法。理解成「出於禮數送出去的東西」，兩個意思就接得起來。
Online Etymology Dictionary (etymonline.com), entry "complimentary"
原始詞典資料3 筆記錄
以下是外部詞典記錄的用法，原文照列，我們還沒有寫成教學內容。上面的說明才是我們自己寫的；有些用法可能上面已經講過了。
complimentaryadj/ˌkɒmplɪˈmɛnt(ə)ɹi/
- 1
In the nature of a compliment.
- a complimentary remark
- But yesterday evening late, when Lewis arrived from down town he found his supper spread, and some presents of books there, with very complimentary writings on the fly-leaves, and certain very complimentary letters, and more or less greenbacks of dignified denomination pinned to those letters and fly-leaves...
- 2
Free; provided at no charge.
- complimentary drinks
- In the evenings, Ward and PJ offer guests a complimentary drink. This gesture seems to reinforce the hosts' desire to make everyone feel welcome.
- 3
With respect to the closing of a letter, formal and professional.
- The complimentary closing is the word grouping used to bring the message or text to a close.
資料來源：英文維基詞典 English Wiktionary（CC BY-SA 4.0）。 原文照列，未經改寫。