"मैं आ रही हूँ।"

Translation: I am coming.

[Margret183301]

Is it possible to simply answer 'आ' if someone is asking me how long he/she will have to wait (just in order to give a very quick response like in English)?

[vinay92]

Simply saying "आ" would be like saying "Come!", as in you are asking the other person to come. (Note: It is in the first level of formality. More formal forms are आओ and आइये).

"Coming!" would be "आ रही हूँ" (i.e, omit the मैं).

[abdowdavram]

No because Hindi is not like east Asian languages
It needs to be said in full or almost in full
Hindustani people often speak very fast anyway so it doesn't matter

[VeehanPirta]

I gave yall 3 lingots