Come, Go and Get

I always have a hard time knowing which one to use in a sentence. I know it depends on to whom [1] you're talking to [2] and where you are at the time you say it. If someone could explain this to me in a simple way, that would be great!

Please tell me if my understanding is correct:
1. When I come home, I will make dinner. (The person I am talking to is at home, and I am not home.)
2. When I get home, I will make dinner. (I am not home, and the person I am talking to is not home.)
3. When I go home, I will make dinner. (Is this the same as 'get'?)

Other ones I find hard to decide which word to use is when I say "I'm coming/going to see you."
What is the difference between these two?

1. When 'who' is the object of a preposition, it becoes 'whom' - although this 'rule' is almost always ignored by native speakers!

2. It is normally good style to avoid putting prepositions like 'to' at the end of phrases, clauses or sentences - but again this is often ignored by native speakers.

In answer to your question, it does depend somewhat on the location of you and person to whom you are speaking. It also depends on the rough timeline of anticipated events. So unfortunately, there isn't a simple answer! :(

"When I come home, I will make dinner."

This sentence would sound strange if the person to whom you're talking is not at your home and will not be at your home when you arrive. If the person is at your home, or is expected to be at your home by the time you arrive, then the sentence would sound right.

"When I get home, I will make dinner."

I think that this is fine in any case: if the person is home or anywhere else. This is the most flexible and probably the most frequently used. "When I get there, I'll call you" when meeting friends at a cinema e.g.

"When I go home, I will make dinner."

To some exent this implies that you a speaking to a person at your current location. Also, going home is an action that starts from the office (e.g.) and continues (e.g. on the train) until you get home. Since we don't usual make our dinner while in transit home, I think this sentence is the least common and would sound a little strange in context.

Rough guide:

"Come" -> when the other person is at your destination

"Get" -> used in many situations

"Go" -> when the other person is at your current/departure location and when the action can be done during the journey

Hope that helps! :)