by sight
by sight — 慣用語
1. able to recognize a person because you have seen them before, even though you ha
面熟；認得臉
看過而認得，但不相識也叫不出名字
able to recognize a person because you have seen them before, even though you have never spoken to them or learned their name.
Eve knew the old postman by sight, but they had never once spoken.
Eve 認得那位老郵差的臉，但兩人從沒講過話。
know someone by sight (recognize without knowing personally)
Most students knew the head teacher only by sight, not as a friend.
大多數學生只是認得校長的臉，並不熟識他。
know only by sight (recognition without acquaintance)
The two neighbours knew each other by sight after years of passing on the stairs.
那兩位鄰居在樓梯間相遇多年後，已經認得彼此的臉。
Christopher recognized the singer by sight, though he could not recall her name.
Christopher 認得那位歌手的臉，卻想不起她的名字。
recognize by sight + still cannot name the person
The café owner knew half the town by sight from years behind the counter.
那位咖啡店老闆在櫃台後站了多年，認得鎮上一半的人。
- know by sight
- recognize by sight
- only by sight
- by appearance
plainer; stresses physical looks rather than the act of recognizing
- by name
knowing who someone is well enough to call them by name
文法句型
know someone by sight
用法筆記
Almost always used with 'know' or 'recognize'. It marks recognition by appearance only, so it is naturally contrasted with knowing someone personally or by name.