Is the word 'mistake' a concrete or abstract noun? [duplicate]

According to Answers.com:

The word mistake is an abstract noun, a word for an error in action or judgement.

Is this correct?

Then, why does it act like concrete nouns such as 'car' when it comes to countability?

Both 'mistake' and 'car' are countable, unless they follow "by".

a. I made three mistakes today. vs. I went there by mistake.

b. I saw three cars today. vs. I went there by car.

Does this prove that 'mistake' is also a concrete noun? Or is 'mistake' still an abstract noun, despite this similarity in countability?

Solution 1:

Being able to count (or not count) a concrete or abstract noun is not a criterion that determines its type.

Some concrete nouns are countable:

✔ Look at that car.
✔ Look at those cars.

Some concrete nouns are not countable:

✔ Help me with my luggage.
✘ Help me with my luggages.

Some abstract nouns are countable:

✔ I made a mistake.
✔ I made a couple of mistakes.

Some abstract nouns are not countable:

✔ How much progress have you made?
✘ How many progresses have you made?

Solution 2:

Concrete nouns represent actual physical objects - table, paint, star, insect etc.

An abstract noun represent something that cannot be physically perceived - idea, ambition, prohibition, concept.

So yes, mistake is an abstract noun. As far as I know abstract nouns are treated exactly the same as concrete ones.

Solution 3:

Actually, a "mistake" can be either abstract or concrete.

"He must have made a mistake doing that math in his head because his answer's wrong."

That's clearly abstract. The mistake is complete intangible and exists merely as an idea.

"Those four cupcakes are mistakes. You can eat the mistakes if you like, but the ones that aren't mistakes are for company."

That's clearly not abstract because you can literally pick up and eat the mistakes.

As for "mistake" being a countable noun, which it is, that has absolutely nothing to do with whether or not it's abstract or concrete. Say a bunch of quarters are on a table. I can say, "The coins are on the table." I can say, "The money is on the table." In those sentences, "coin" is a count noun and concrete and "money" is a non-count noun and concrete. They're both concrete nouns as they both indicate the exact same tangible objects lying on the table, so being concrete doesn't preclude a noun from being non-count and being a count noun does't mean a noun is necessarily concrete, as the very first example sentence above demonstrates.