disclaimer: the following may not be 100% correct. It's just a part of what I learn from my experiences). Any experts who spot any mistakes, please correct me (and I get to learn something new
)
just repeating some basics to add on in case you find markdweaver's post a little advanced (bringing in culture/politeness etc)
first, I think you should know (if you don't yet) that kureta(くれた) is really the ta(た)-Form of kureru(くれる)(also 呉れる though it is more common to use only kana).
kureru is a special case of ageru (to give) where the general "direction of giving" (for lack of a better phrase) is towards you or your organization.
Example 1:
A gives B an apple.
AさんはBさんにりんごをあげました。
--use ageru cause the "direction of giving" *is not* towards the speaker
Example 2:
A gives me an apple.
Aさんは私にりんごをくれました。
--use kureru cause the "direction of giving" *is* towards the speaker
Example 3:
My sister gives me an apple.
姉は私にりんごをくれました。
--use kureru cause the "direction of giving" *is* towards the speaker
Example 4:
I give my sister an apple.
私は姉にりんごをあげました。
--use ageru cause the "direction of giving" *is not* towards the speaker
Example 5:
A gives my sister an apple.
Aさんは姉にりんごをくれました。
--use kureru cause the "direction of giving" *is* towards the speaker(speaker's family: my sister is "closer" to speaker than A)
Example 6:
My brother gives my sister an apple.
兄は姉にりんごをあげました。
--use ageru cause the "direction of giving" *is NOT* towards the speaker(both my sister and my brother are part of the family, so they are "equidistant" from me, so the direction of giving is not towards me)
Example 7:
(Say I live in country X)
Country Y gives Country X an apple. (lol..awkward statement, but bear with it for illustration purposes)
Y国はX国にりんごをくれました。
--use kureru cause the "direction of giving" *is* towards the speaker(speaker's country X is closer to speaker than country Y)
Example 7 can be extended to any organization like school, society, firm/company, country, planet (if exchanging gifts with ETs)...
Common pitfall: Also note that ageru and kureru is for GIVING. A common mistakes among beginners (myself included in the past) is confusing kureru with RECEIVING. "to receive" is a totally different verb morau (もらう/貰う).
Hope this is of help