What is the difference between 大事 (daiji) and 大切 (taisetsu)?


These are two words that seem like they are basically interchangeable at most
levels, as they generally are. The difference between them appears to be
small, but what _is_ the difference, if one exists? I feel like there are
certain situations in which you would use 大事 and certain situations in which
you would use 大切. For example, I would associate 大切 with sentimental things
because of the 切 in it that comes from 切ない, things like memories, or a present
that someone gave you, whereas I would associate 大事 with things that are of
pressing importance, closer to 重要. But this does not appear to be the case, as
I occasionally see 大切 used where I would normally expect 大事, like 大切なお知らせ,
with more of a feeling of 緊急 or urgency. There are sources
[here](http://detail.chiebukuro.yahoo.co.jp/qa/question_detail/q1218649557)
and
[here](http://detail.chiebukuro.yahoo.co.jp/qa/question_detail/q1435775334)
which address this, but they both arrive at the same wiggly uncertain feeling
that 大切 is more emotional and 大事 is more about urgency while admitting that in
just about any situation the two can be used interchangeably.

大辞林 isn't much help on the subject. For both it says 重要であるさま, and in
[大事](http://dictionary.goo.ne.jp/leaf/jn2/133271/m0u/%E5%A4%A7%E4%BA%8B/) it
includes 大切に扱う and in
[大切](http://dictionary.goo.ne.jp/leaf/jn2/133741/m0u/%E5%A4%A7%E5%88%87/) it
includes 大事にする. The only hint I can get from the dictionary entry is in the
following for 大切:

> **大切**
>
> 丁寧に扱って、大事にするさま。「本を―にする」「命を―にする」

And in the following for 大事:

> **大事**
>
> 重要で欠くことのできないさま。ある物事の存否にかかわるさま。「―な用を忘れていた」「今が―な時期だ」

This lends something to the idea of 大切 as a more 'polite' form of importance
while 大事 is more about the concept that something is fundamentally _necessary_
and in that regard important. However both of the entries generally seem to be
nearly the same with different wording.

Is there a practical difference, and if so, what is it? Does using one over
the other have any impact on the actual meaning of a sentence? When can they
_not_ be used interchangeably (outside of set phrases like お大事に)?




As far as I can tell, you've basically hit the nail on the head with the
differences between the two.

`大切` is listed in the `日本国語大辞典` as (I've removed some of definitions I think
are less important):

> ...  
>  2: 一番必要で、重んずべき物であること。貴重であること。肝要であること。  
>  ...  
>  4: 心をくばってていねいに取り扱うこと。大事にすること。かけがえのないものとして心から愛するさま。

So using definition 2, something which is of utmost
importance/precious/essential and should be given great regard to, which I see
in reference to things which are done (which I think would e.g. be used like
`体を大事にするのが大切です`, though `大切`/`大事` could be exchanged there as they can be very
similar).

And using definition 4 is with the emphasis on the "treat something
mindfully/carefully" and "love something from the bottom of one's heart (`心`)
as if there's no substitute" which I see more for describing things/people as
in `大切な（物・者）` (though it's also listed as "treated as `大事`").

* * *

And for `大事` (as an adjective):

> 1: かけがえのないものとして大切にするさま。大切。  
>  2: 評価して心にとめるべきさま。重要で根本にかかわるさま。

So it's used for things which are to be treated as `大切` as if they can't be
replaced, or a state where something should be valued and given heed to, so
there's a lot of overlap, but I believe that `大切` is more about the
`心`/sentimental/emotional sense and is more subjective and `大事` more about
being fundamentally important/valuable and is more objective.

Note that `大事` can also be used as a noun to mean an important task/large
undertaking (as in `大事業`) or an important thing etc.




As far as I can tell, you've basically hit the nail on the head with the
differences between the two.

`大切` is listed in the `日本国語大辞典` as (I've removed some of definitions I think
are less important):

> ...  
>  2: 一番必要で、重んずべき物であること。貴重であること。肝要であること。  
>  ...  
>  4: 心をくばってていねいに取り扱うこと。大事にすること。かけがえのないものとして心から愛するさま。

So using definition 2, something which is of utmost
importance/precious/essential and should be given great regard to, which I see
in reference to things which are done (which I think would e.g. be used like
`体を大事にするのが大切です`, though `大切`/`大事` could be exchanged there as they can be very
similar).

And using definition 4 is with the emphasis on the "treat something
mindfully/carefully" and "love something from the bottom of one's heart (`心`)
as if there's no substitute" which I see more for describing things/people as
in `大切な（物・者）` (though it's also listed as "treated as `大事`").

* * *

And for `大事` (as an adjective):

> 1: かけがえのないものとして大切にするさま。大切。  
>  2: 評価して心にとめるべきさま。重要で根本にかかわるさま。

So it's used for things which are to be treated as `大切` as if they can't be
replaced, or a state where something should be valued and given heed to, so
there's a lot of overlap, but I believe that `大切` is more about the
`心`/sentimental/emotional sense and is more subjective and `大事` more about
being fundamentally important/valuable and is more objective.

Note that `大事` can also be used as a noun to mean an important task/large
undertaking (as in `大事業`) or an important thing etc.

