Correct word for “indeed”

Question

What is the correct translation for "indeed"? I found 実際{じっさい}に and 確{たし}かに.

If both are correct, what is the difference?

Thanks.

Answer 1

• When you want to tell that you have a clear idea to agree with the proposition in question, then use 確かに:

  確かにあなたは怠け者だ。

• When you assume (often falsely) that the origin of the idea is the second person, and you agree with it, use なるほど:

  なるほどあなたは怠け者だ。

• When you want to temporarily accept an idea and continue with a statement pointing to the opposite direction, you can use the ones above:

  確かにあなたは怠け者だが、それはそれでよしとしよう。
  なるほどあなたは怠け者だが、それはそれでよしとしよう。

• When you want to exemplify, or formally prove an abstract statement, use 実際. Unlike 確かに or なるほど, the first person is the one who is showing it to the second person.

  彼は怠け者だ。実際、彼の文には句読点がない。
  全ての人が怠け者というわけではない。実際、ちゃんとした文章を書く人もいる。

Answer 2

If you're looking for a translation to the (mainly British) interjection "Indeed!" which you seem to hint in a comment, you should neither use 確かに nor 実際に.

The below are common colloquial expressions:

へー　used a lot in Japan for expressing awe, surprise or disbelief etc. Has back-channel qualities as well.
本当(に)？ Really?
マジ(で)？ Seriously? (Slangy, but very common among mainly younger speakers)
う(っ)そー　You're lying!
まさか　You don't say... (expressing some level of disbelief)