What is the difference between 「本物」 and 「本当」?

Question

Originally, I had the following sentence:

人形は本当の人のように動きました。

A Japanese native corrected to be:

人形は本物の人のように動きました。

I just want to understand what the difference between the 2 words is, and why 本物 is more appropriate in this sentence.

Answer 1

本当

• is an adjective itself (some people call it no-adjective; 本当だ "be true", 本当に "really")
• true as opposed to wrong, apparent, untrue, lying
• proper as opposed to impure, inaccurate, questionable
• real as opposed to fictitious, imaginary

本物

• is a noun itself (本物だ "be a/the true thing", 本物に "to a/the true thing")
• a genuine thing as opposed to a fake, pretended one
• a full-fledged thing as opposed to a substandard one

In this context, the doll (or puppet?) is an imitation of real human, so 本物 is felt somewhat more suitable, but it doesn't mean 本当 is invalid or unacceptable here. Besides, the most ideal wording I think would be:

人形は本物の人間のように動きました。

Answer 2

A dictionary says interestingly that 本物 means 本当のもの(こと) and 本当 means 本物のもの(こと), that is to say, they have the same meaning of "real".

However 本当 has some meaning like "true", and 本当 may be used more as the meaning of "true" than "real", so Japanese native might correct 本当 as 本物. I also think 本物　is more common as the meaning of "real" than 本当.

Answer 3

• 本当 = really/ the truth/ truthly (adverb)
• 本物 = the actual/ real object (object)

In your sentence 本当の人 does not make any sense. Common use with 本当 is:

• 本当は (The truth is)
• 本当に？ (Oh really?)
• 彼は本当のことを言っている (He is telling the actual truth)

When people talk about 本物, they are usually comparing the fake/ similar vs the real one. For ex:

• このプラスチック食品はおいしそう。本物みたい。(This plastic food looks delicious. Like the real one (food).)
• 仕様はこうなっているが、本物はどうなるだろう。(The spec is defined like this, but I wonder how the actual thing will be.)