To cross-check is to check something a second time using a different source or a different method, so that the two answers can be compared. The important part is the word different.

To cross-check is cross-check 就是 using a different source or a different method用不同的來源或不同的方法 to check something a second time把一件事再查核一次， so that好讓 the two answers兩個答案 can be compared可以互相比對。 The important part is重點就在 the word different「不同」這個字。

Reading your own answer twice is not cross-checking; adding the numbers again on the same calculator is not cross-checking. Asking a second person, looking in a second book, adding the column from the bottom instead of the top — that is cross-checking. The idea is that two ways of getting to the same place are far more convincing than one way done twice.

Reading your own answer twice把自己的答案再讀一遍， is not cross-checking不算 cross-check； on the same calculator用同一台計算機 adding the numbers again把數字再加一次， is not cross-checking也不算。 Asking a second person問第二個人、 looking in a second book查第二本書、 from the bottom instead of the top從底下往上、而不是從頂上 adding the column把整欄再加一次—— that is cross-checking這才是 cross-check。 The idea is道理是： two ways of getting to the same place兩條路走到同一個地方， than one way done twice比起一條路走兩遍， are far more convincing可信得多。

It is used by journalists checking a story against a second witness, by accountants checking figures against a bank record, by researchers checking data against another dataset. It is also a noun: "a quick cross-check with the original list". The tone is careful and a bit professional; among friends you would just say "let me double-check".

It is used by journalists記者會用它： checking a story against a second witness拿第二位證人核對報導； by accountants會計師 checking figures against a bank record拿銀行紀錄核對數字； by researchers研究者 checking data against another dataset拿另一份資料集核對數據。 It is also a noun它也是名詞： "a quick cross-check with the original list"跟原始清單快速比對一下。 The tone is careful and a bit professional語氣謹慎、帶點專業味； among friends朋友之間 you would just say你多半只會說 "let me double-check"我再確認一下。

Worth knowing: double-check and cross-check are not quite the same. Double-check only means check again — same method is fine. Cross-check carries the promise of a second, independent source.

Worth knowing值得一提： double-check and cross-check這兩個字 are not quite the same不完全一樣。 Double-check only means Double-check 只是說 check again再查一次—— same method is fine同一個方法也沒關係。 Cross-check carries the promise of Cross-check 則帶著一個承諾： a second, independent source第二個、獨立的來源。

In ice hockey, by the way, cross-check means something completely different — hitting another player with the stick held in both hands — but that meaning is not the one here.

In ice hockey在冰上曲棍球裡， by the way順帶一提， cross-check means something completely different cross-check 是完全不同的意思—— with the stick held in both hands雙手握著球桿 hitting another player去撞另一名球員—— but that meaning is not the one here但那個意思不是這裡講的這個。