每兩週一次
這一支把「二」讀成兩個星期：中間隔兩週，再來一次。這是日常最常遇到的讀法，薪水和刊物尤其如此。
adjective · B2
Happening, or coming out, once every two weeks.
每兩週一次的
核心畫面
Think of the word as three pieces stuck together: bi (two), week, and the -ly that turns it into a description. What the pieces never settle is what the two counts. Two weeks between one thing and the next? Or two of them inside one week? Both readings are alive, and the word will not choose for you. So the useful picture is not a calendar — it is a question mark over the number two. Good writing answers that question by naming the days.
biweekly 可以想成三塊拼起來的字。bi 是「二」，week 是「週」，-ly 把它變成描述。真正沒有定下來的…更多收起
biweekly 可以想成三塊拼起來的字。bi 是「二」，week 是「週」，-ly 把它變成描述。真正沒有定下來的，是那個「二」在數什麼。是兩個星期隔一次？還是一個星期裡兩次？兩種讀法都有人在用。這個字不會替你選。所以比較有用的畫面，不是一張行事曆，而是「二」上面的一個問號。寫得好的句子，通常會把日期補出來回答它。From the word’s history
Wiktionary records the word as bi- + week + -ly, and adds that the twice-a-week reading can be analysed instead as bi- + weekly. The two possible splits of the same string are exactly where the two meanings come from.
Wiktionary 記錄這個字來自 bi-（二）加 week（週）加 -ly。它同時指出，「一週兩次」那個意思可以拆成 bi- 加 weekly。同一串字母有兩種拆法，兩個意思就是從這裡分出來的。這不是後人硬湊的巧合，而是構詞本身就留下的縫隙。
Wiktionary entry for biweekly, kaikki extract source_ref kaikki:3f6f69a190036ae4:397071624 — etymology_text: From bi- + week + -ly. The sense referring to twice a week can be analyzed as bi- + weekly.
Two branches
一週兩次
這一支把「二」讀成一個星期裡的兩次。方向和上一支相反，字卻長得一模一樣——這就是那個問號真正的代價。
adjective · B2
Happening twice in the same week.
一週兩次的