I had a same question when I heard 'Can I come??' for the first time.
I asked my teacher why do you use 'can' as 'go'?, he said that it's a same mean. If you say 'Sorry I can't go', it's also correct!
ゆぅみんさん > that's a good way to think of it in English.
If the person you are talking to is here, use go.
If the person you are talking to is there, use come.
If the person you are talking to is *going to* be there, use come.
If the person you are talking to is *going to* be here, use go.
Face-to-face:
Shall I go to your house now?
Shall I come to your house later? (The person will have arrived there by then)
On the phone:
Shall I come to your house?
When you get here, shall I go back to work? (The person will have arrived here by then)
How do these conversations sound in Japanese? Would you use 行くor来る?
There is a similar topic "take vs bring." This topic is imagined kind of differently
between English and Japanese.
話し手:you
聞き手:the person to whom you are talking
In English the position of the person to whom you are talking is important (the basis).
聞き手中心
●come
You approach someone to whom you are talking.
●go
You leave someone to whom you are talking.
In Japanese your position is important (the basis).
話し手中心
●来る
You move from somewhere to here.
●行く
You move from here(somewhere) to somewhere.
If I translate these conversations from English to Japanese, they will look like
the below sentences.
【Face-to-face】
Shall I go to your house now?
I(話し手) here ⇒ your house(somewhere)
今、あなたの家へ行きましょうか?
Shall I come to your house later?
(The person will have arrived there by then)
I(話し手) somewhere ⇒ your house(somewhere)
あとで、あなたの家へ行きましょうか?
【On the phone】
Shall I come to your house?
I(話し手) here ⇒ your house(somewhere)
あなたの家へ行きましょうか?
When you get here, shall I go back to work?
(The person will have arrived here by then)
I(話し手) here ⇒ work(somewhere)
あなたがここに着く頃(時)、私は仕事へ戻り(戻って行き)ましょうか?