The usage of 去 and 来

去 (qù) and 来 (lái) are directional verbs that respectively mean “to go” and “to come”, therefore suggesting distancing and approaching with respect to the person who is talking.

你什么时候会去北京？
nǐ shénme shíhòu huì qù běijīng
[you when FUT to-go Beijing]
When will you go to Beijing?

The person who is talking is not in Beijing.

我爸爸会来机场接我。
wǒ bàba huì lái jīchǎng jiē wǒ
[I dad FUT to-come airport to-pick-up I]
My dad will come to the airport to pick me up.

The person who is talking is at the airport.

去 (qù) and 来 (lái) can also be used together with other verbs to indicate the direction of an action.

秘书：总经理，周先生来了。
总经理：让他进来吧！
mìshū: zǒng jīnglǐ, zhōu xiānshēng láile
zǒng jīnglǐ: ràng tā jìnlái ba!
[secretary: president, Zhou Mister to-arrive ASP
president: to-let him to-enter to-come MOD]
Secretary: President, Mister Zhou is here (arrived).
President: Let him in!

In this case, the secretary and the president are both in the same place (the president’s office) and 来 is used together with 进 “to enter” because it refers to Mister Zhou, who is outside the office.
Assuming the next scene, we could have

秘书：周先生，您可以进去。
mìshū: zhōu xiānshēng, nín kěyǐ jìnqù
[secretary: Zhou Mister you(polite form) can to-ender to-go]
Secretary: Mister Zhou, you can go in.

In this case, both the secretary and Mister Zhou are outside the president’s office and 去 is used because the direction indicated by the verb 进 is that towards the inside of the office where the president is.

Cover background picture by Thong Vo (unsplash.com)