Is there difference between 大事／大した


When would one be used? I don't understand the difference between them.




事【じ】 is a matter, so 大事【だいじ】means a "serious matter".

大【たい】した places less emphasis on the "matter" and more on being "big", so can
simply mean "very" or "much".

As an example

> 国家安全保障【こっかあんぜんほしょう】の大事【だいじ】 - a matter of national security

and

> 彼女【かのじょ】は大【たい】した歌手【かしゅ】になるはず - she will definitely become a (very big)
> singer

As per their negative counterparts, I find that in a colloquial sentence the
following would seem a bit more formal:

> 大事【だいじ】ではない ー (it's not a big issue)

whereas this sounds more natural:

> 大【たい】したこと（では）ない ー (no biggie)




事【じ】 is a matter, so 大事【だいじ】means a "serious matter".

大【たい】した places less emphasis on the "matter" and more on being "big", so can
simply mean "very" or "much".

As an example

> 国家安全保障【こっかあんぜんほしょう】の大事【だいじ】 - a matter of national security

and

> 彼女【かのじょ】は大【たい】した歌手【かしゅ】になるはず - she will definitely become a (very big)
> singer

As per their negative counterparts, I find that in a colloquial sentence the
following would seem a bit more formal:

> 大事【だいじ】ではない ー (it's not a big issue)

whereas this sounds more natural:

> 大【たい】したこと（では）ない ー (no biggie)

