We see time as "time" not as tense. So it 'only' 3 "times": past, present (now) and future. We look at time through the verb aspect (action without thoughts of result/ end = imperfective verb; action with result = perfective verb).
-jeść (imp.)/ zjeść (perfective) - the probability of achieving a result increases
- Zamierzamy jutro (imperfective verb) - We are going to do something but we don't know if we end it.
- Jutro jemy obiad u ciebie. - Tomorrow we're having dinner at your place. // But we are not sure if we will do it.
- Jutro będziemy jedli // Jutro będziemy jeść... - Tomorrow we will be eating...
- Zamierzamy jutro (perfective verb) - We plan to have a result.
- Jutro zjemy obiad z tobą. - Tomorrow we will have dinner with you. // It's promise.
To distinguish "time" we use time adverbials (timekeepers).
Latamy do Londynu - We (often) fly to London.
Często latamy do Londynu - We often fly to London.*
Lecimy do Londynu. - It can means that: "We are flying to London (now)" or "We are going to fly to London (in the specific future).
Właśnie lecimy do Londynu - We're just flying to London.
Jutro lecimy do Londynu - We're flying to London tomorrow.
Kiedy lecimy do Londynu? - When are we flying to London? /We aren't doing it yet otherwise we wouldn't be asking :) /
O której lecimy do Londynu? - What time do we fly to London?
Do you see some regularity? Adverbial time is at the beginning of the sentence. From the start we know about what "time" we speak. We can change word order to accent the acction (the verb):
Nie uwierzysz, lecę właśnie do Londynu. - You will not believe me, I'm flying to London.
Polish order is not so free, like some people can think :) Yes, you can often say what you want, but your interlocutor probably will be having hard time to decifer WHAT EXACTLY you mean/want. We attach great importance to emphasizing specific words not only in the sentence's order, but above all in the intonation.
The basic (standard) word order is:
question mark // time adverbial / subject / verb / object
When we are going home? is bad, the true is When are we going home? mhm
"When we are going home?" isn't a correct word order of an English question.