This symbol - I still can’t place it.

（この記号だ…まだわからない。）
　BBCドラマ「SHERLOCK」エピソード2 "The Blind Banker" より。2件の殺人にまつわる謎の暗号に取り組むホームズ。

• placeは動詞で「〜を思い出す、突き止める、見分ける」という意味で使うことがある。久しぶりに会った人が誰だか思い出せない時とか。基本的には否定文で使う。（(usually used in negative sentences) to recognize someone or something and be able to identify them/it／to recognize someone or remember where you have seen them or how you know them／to identify by connecting with an associated context／to identify or classify in a particular context／remember where one has seen or how one comes to recognize (someone or something)）
• placeという単語を使う事で、過去のいろんな暗号の事例や自分の知識・経験などと照らし合わせても結びつくものが思い出せない、わからない、解けない、というニュアンスになるのかなと思った。
  • I've seen her somewhere before, but I can't quite place her.
  • I've seen her before but I just can't place her.
  • His accent was impossible to place.
  • She looks familiar but I can't place her - did she use to work here?
  • I could not place that person's face.
  • She eventually said she couldn't place him.