What is the *proper* differentiation between 来る and 行く?

Question

In many beginning Japanese classes, 来る【くる】 and 行く【いく】 are presented as "to come" and "to go," respectively. Dictionaries generally also define them this way. However, every once in a while in more advanced classes, teachers will mention that this is not actually the case; these words are used differently in Japanese than their English (pseudo-)counterparts.

I cannot for the life of me remember the proper way to understand the differentiation between these verbs, past "come" and "go," a fact which is most embarassing.

Can someone please explain how these words are different than the English "come" and "go" in their usage?

Related question: Difference between -ていく and -てくる

Answer 1

As usual, I'll go for examples which should come in handy. Check the emphasized words. (The translations are not natural, but it's not the point here.)

Sample 1

Won't you come visit me in France?
フランスに来ませんか？待っていますよ！

Yes, I will go to France. We will go see the Arc de Triomphe.
はい、フランスに行きますよ。一緒に凱旋門を見に行きましょう。

Great. Mark came last summer already.
良かった。去年の夏はマークさんが来たよ。

Sample 2

Will you come/go to John's party tonight?
今晩、ジョンさんのパーティに行きますか？

No, I won't go to John's.
いいえ、行きません。

Paul is not coming/going either.
ポールさんも行きません。

Sample 3

Come here!
来てください!

Yes sir! I'm coming right away.
はい、すぐ行きます。

Summary

Tarou is at place A, Jun is at place B. Tarou calls motions towards A as "来る". Tarou calls motions away from A as "行く". Tarou calls motions towards Jun as "行く".

行く/来る is from-here/to-here relatively to the person who uses the verb now. (I suddenly have a doubt for a situation like "will you visit me at my new home when I moved to France". I think "来る" would still be good, because it's still about the narrator being reached.)

Answer 2

As Ignacio Vazquez-Abrams says, the key is the difference in point of reference. So when the first and the second person's perspective are the same, Japanese and English have the same distinction for these words. Difference between Japanese and English appears when the first and the second person's perspective are different. That is typical when someone is calling another. A different famous example is the words said at sexual climax. In English, people say I'm coming. This is in second person's perspective. In Japanese, people say 行く. This is in first person's perspective.

Answer 3

「来る」 implies motion or action towards or ending at the speaker or the speaker's current situation, whereas 「行く」 implies motion or action away from or beginning at the speaker or the speaker's situation.

Answer 4

There are many cases where the Japanese "KURU/KIMASU" really means the same as the English "come", and the Japanese "IKU/IKIMASU" really means the same as the English "go", but there's a certain case where it's used differently. Let's look at the following 4 scenarios.

This video explains with animations: I'll come or I'll go?

Basically,

KURU/KIMASU - Someone or something is moving toward you or whoever the speaker is

IKU/IKIMASU - Someone or something is moving AWAY from you or whoever the speaker is. When you are the speaker, you will still be moving away from yourself(the speaker) or your current position by "going somehwere"

Scenario 1:

In this scenario, you are talking with A about "B coming" to you (B moving toward you). In English, you'd say "B comes" because B is moving toward the speaker, which is you, the white cat in the picture. It's the same thing in Japanese, so you'd call B's action as "KIMASU" because B is moving toward the speaker.

Scenario 2:

In this scenario, you are talking with A about A's action. In English, you'd ask "Will you come?" because you want to know whether A will be coming toward you, the speaker (the white cat in the picture). It's the same thing in Japanese, so you'd call A's action as "KIMASU" because A is moving toward the speaker.

Scenario 3:

In this scenario, you are talking with A about you going to the third person, B. You are moving away, so you'd tell A "I'll go (to B)" in English. Again, it's the same thing in Japanese, you are moving away from the speaker, which is yourself, the white cat in the picture, so you'd call your own action as "IKIMASU"

Scenario 4:

In this scenario, you are talking with A about you going to A. In English, "come" is used when you are moving toward the person you are talking to, so you'd say "I'll come (to you)". BUT, in Japanese, it doesn't matter where you are moving to. It doesn't matter that you are moving toward the person you are talking to. As long as you are moving away from the speaker, which is yourself, the white cat in the picture, you'd call your action as "IKIMASU".

Hope this helps.