So I'm basically filling in for your skull.

（じゃあ僕はさしずめ君の骸骨の代わりをしてるってことかい？）
　BBCドラマ「シャーロック」エピソード1 "A Study in Pink" より。事件についてワトスンに話し始めるホームズ。警察にもまだ話していない話をどうして自分にするのか問いかけるワトスンに、「ハドスン夫人が僕の骸骨を片付けてしまったんだ」と理由を答えるホームズ。それを聞いたワトスンのひとこと。

• "fill in for"で、「〜の代わりに」という意味に。ある仕事をするはずの人がそこにいないので、というニュアンスが隠れている。（do someone's job because they are not there／ to substitute for someone or something; to take the place of someone or something ※substitute：〜の代わりをする／to do someone's job for a short time while they are not there／to do someone else's work for them because they cannot or will not do it themselves）
  • I will have to fill in for Wally until he gets back.
  • I don't mind filling in.
  • I'm filling in for Joe for a few days.
  • Volunteers would fill in for teachers in the event of a strike.
  • I'm not her regular secretary - I'm just filling in.
  • I was away for a few days, so they had to get someone to fill in for me.
• あと、「結局のところ、要約すると、まとめると、つまり」といったニュアンスで basically が使われているのもちょっとメモしておきたい。（used to indicate that a statement summarizes the most important aspects, or gives a roughly accurate account, of a more complex situation／For the most part; chiefly／used to show that a statement is expressing the most important reason for something）
  • I basically played the same tunes every night.
  • Basically, I'm just lazy.
  • Basically we had underestimated mother nature.
  • Basically, there's not a lot we can do about it.
  • And that's it, basically.
  • Why don't you like him?---Basically, I think he's crazy.
  • We'd like to buy a new car, but, basically, we just don't have enough money.

（DVDはリージョン違いなのでご注意を！）