The difference between ～きてくれる vs ～くれる


Is there a strict rule for when one _should_ use「～てきてくれる」vs 「～てくれる」?

I thought the part about being the benefactor is already captured by 「くれる」.
The sentence I am thinking about is the following:

> 両親は旅行のたびに、各地のお土産を買ってきてくれるんです。

Is it not possible to drop the 来て from the sentence? What did I lose if I drop
it?




I think the 'きて' here is only saying they came back with the gifts.

The nuance in English would be the same as: "お土産を買ってきてくれる" "...bring back
souvenirs for me(that they buy)"

"お土産を買ってくれる" "...buy souvenirs for me"

The difference is subtle. Both phrases can be used in the same context but
offer varying degrees of detail. Not much different from how we use English.

For me, as a writer, the difference is more noticeable. With the ”きて” I can
picture them giving the gift, I see expressions, I feel the joy, excitement.
Without it, it's not that I get a negative impression but I might only picture
them buying the gift. Different experience.

