milega nahi hai is wrong,
nahi milega is correct.
Here 'milna' is used in terms of availability only. ur translation is not applicable in every situation as,
milna is also used in sense of meeting, getting or mixing.
Word for imPossible like in mission impossible is asambhav, possible-sambhav.
Else u r right everywhere
ye asambhav hai(it is impossible)
ye nahi ho sakta.(it is not possible)
ye ho sakta hai/ye sambhav hai(it is possible)
to make question is it..?
Just add kya at start.
This is different case, u r correct in specific condition only
chai we consider as femenine so it should be milegi, but no matter even if u say milega everyone will get u.
Shake hands - haat to mila
ja / haat mila na
its 'haath' not haat
these seem to be very informal sentences n should be used with frnds n younger family members.
Haath mila naa sounds as if u r very informaly requesting someone to shake hands.
'Haath milaaiye' will be good
pronounce as 'mile'ga
i like in bit, le like lay/say in english n ga
mi-lay-gaa
'mile'gaa.
There are alternates also but i would like not to increase the complicacy :)