First-hand describes knowledge that came to you directly — you saw it, you did it, you were there, or the person it happened to told you themselves. Nobody passed it along in between. 'She has first-hand experience of the job' means she actually did the job. 'I heard it first-hand from the doctor' means the doctor told you, not a friend of a friend.

First-hand describes描述的是 knowledge that came to you directly直接來到你這裡的認識——you saw it你親眼看到、you did it你親手做過、you were there你人在現場，or the person it happened to或者事情發生在誰身上，told you themselves那個人親口告訴你。Nobody沒有任何人 passed it along in between在中間轉手傳過它。'She has first-hand experience of the job' means意思是 she actually did the job她真的做過這份工作。'I heard it first-hand from the doctor' means意思是 the doctor told you是醫生親口告訴你的，not a friend of a friend不是朋友的朋友。

The picture behind the word is of something passing from hand to hand: your hand is the first one it lands in, so it has not been changed on the way. That is the whole point of the word — it is about how trustworthy the information is. Second-hand knowledge is 'someone told me'; first-hand is 'I know'.

The picture behind the word這個字背後的畫面，is of something passing from hand to hand是東西一手傳一手：your hand is the first one it lands in你的手是它落進的第一隻手，so it has not been changed on the way所以它一路上沒被改過。That is the whole point of the word那就是這個字的全部重點——it is about它講的是 how trustworthy the information is這個訊息有多可信。Second-hand knowledge is二手的認識是 'someone told me'「有人跟我說」；first-hand is第一手是 'I know'「我知道」。

It works two ways in a sentence. Before a noun it is an adjective: first-hand experience, a first-hand account, first-hand knowledge. After a verb it is an adverb: 'I saw it first-hand', 'I learned that first-hand.' Both are common.

in a sentence在句子裡，It works two ways它有兩種用法。Before a noun在名詞前，it is an adjective它是形容詞：first-hand experience第一手經驗、a first-hand account一份第一手記述、first-hand knowledge第一手的認識。After a verb在動詞後，it is an adverb它是副詞：'I saw it first-hand'我親眼看到、'I learned that first-hand.'我親身學到。Both are common兩種都常見。

Now the honest part: 'first-hand experience' is one of those phrases people say when the experience was actually a bit thin. A politician says he has first-hand experience of poverty because he visited a poor area for one afternoon. The word carries weight, so people borrow that weight. Careful listeners notice.

Now the honest part接下來是老實話：'first-hand experience' is one of those phrases是那一類的話——when the experience was actually a bit thin當經驗其實有點薄的時候，people say人們才特別會說。A politician says一個政治人物說 he has first-hand experience of poverty他對貧窮有第一手經驗，because因為 he visited a poor area他去過一個貧困地區，for one afternoon一個下午。The word carries weight這個字有份量，so people borrow that weight所以人們去借那個份量。Careful listeners細心的聽者 notice會注意到。

Also, do not mix this up with second-hand meaning used or not new — a second-hand bicycle. That is the same word doing a different job, and there is no matching 'first-hand bicycle'; for that we say 'new' or 'brand new'.

Also另外，second-hand meaning used or not new意思是「用過的、不是新的」的 second-hand，do not mix this up with別和這個搞混——a second-hand bicycle一輛二手腳踏車。That is the same word那是同一個字 doing a different job在做另一份工作，and there is no matching 'first-hand bicycle'而且沒有相對的 'first-hand bicycle'；for that那種情況，we say我們說 'new' or 'brand new'。