A going in, and the whole cup changing. Picture a drink that is flat, or a bit bitter. You stir in one spoon of honey, and the taste becomes easy to swallow. Nothing has been taken out; something small has been put in, and that is enough to change how the whole thing goes down. Every use of sweeten can be read as that same , with the honey wearing a different shape each time — a bonus added to an offer, a good year added to a hard character, a warm phone call added to a bad week.
From the word’s history
The source says sweeten is simply sweet plus the ending -en, which makes a verb meaning 'make it become that'. So the spoonful picture is built into the word itself: sweet is the taste, -en is the act of putting it there.
資料說 sweeten 就是 sweet（甜的）加上字尾 -en，-en 的作用是「使變成…」。所以上面那匙蜜的畫面，其實就寫在字的結構裡：sweet 是味道，-en 是把它放進去的那個動作。資料還提到，這個字取代了中古英語從古法文借來的 doucen。
Wiktionary entry for sweeten (source_ref kaikki:3f6f69a190036ae4:925250744): "From sweet + -en. Eclipsed non-native Middle English doucen and endoucen, borrowed from Old French adoucir and endoucir."
登入就可以看每一支怎麼連回核心畫面。