Grammar Comparison: ていく and てくる

Grammar comparison: ていく and てくる

I. Overview:
＊ When using ～てくる ・ ～ていく, the speaker views position and time entirely from their own standpoint.
＊ Examples:
犬が向こうから走ってくる。(The dog comes running towards me from over there.)
犬が向こうへ走っていく。 ( The dog runs (from me) over there.)

II. Distinguishing their uses:
❤ Meaning: Movement (going, coming) that happens after some action.
❤ Examples
– 出かけるとき、天気予報を見てきました。
Before going out, I checked the weather forecast.
荷物はここに預けていこう。
Come and leave your luggage here.

-「～てくる」だけ
コンビニでジュースを買ってきます。
I'll go to the convenience store to buy a soft drink (and come back).
ちょっと外でたばこを吸ってきます。
I'm just going out for a smoke. (then coming back to the room)
❤ note: Refers to the speaker going to do something and then returning to the starting point.

-「～ていく」だけ
空港へ行く途中でお金をおろしていこう。
On the way to the airport I'll withdraw some money.
途中の郵便局で書留を出していった。
❤ note: Refers to the speaker going to do something without returning to the starting point (of the action).

See also:
50 Common N3 Japanese Grammar Structures
Soumatome N3 Grammar Collection