くれる is generally taught as part of a set of 3 verbs that are regularly used for giving and receiving in Japanese. These verbs are
くれる,
あげる, and
もらう.
くれる means ‘to give’ (to you, or someone that is part of your ‘in’ group).
-
おばあちゃんはいつもお菓子（かし）をくれる。
My grandmother always gives me candy.
-
毎年（まいとし）、彼女（かのじょ）が手紙（てがみ）をくれる。
Every year, my girlfriend gives me a letter.
-
母（はは）は毎日（まいにち）私（わたし）にクッキーをくれる。
My mother gives me cookies everyday.
With
くれる and
あげる, they both function in the regular way you would expect (regarding particles). This means that
が will always mark the giver (the person performing the action), and
に will mark the recipient (the person that is the ‘destination’ of the thing that is given). This means that
を will be used to mark the ‘object’ that is given, as is usually the case.
The giver/recipient are often omitted from sentences with
くれる, as one/both are usually obvious from context, or the sentence may be focussing on the object.
As can be seen here, the same nuance is kept, even when things are omitted.
What someone considers their ‘in’ group will be different for each person, but usually consists of members of your family, clubs that you are in, or something similar that has a ‘group’ atmosphere (that you are a part of).
The giver will always be someone that is more distant than the people that are in the ‘group’.
-
近所（きんじょ）の人（ひと）が旅行（りょこう）から帰（かえ）って来（き）て、父（ちち）にお土産（みやげ）をくれた。
When the neighbors return home from traveling, they give my father souvenirs.
-
先生（せんせい）がクラブ仲間（なかま）のとしこちゃんに花（はな）をくれた。
The teacher gave flowers to my club member, Toshiko-chan.
When we want to say that we (or someone else) gave something to someone that is not in our ‘in’ group, we will need to use あげる instead.