Translation:Usually they go home at night time.
Is there any difference between "umumnya" and "biasanya"?
Can they always be used interchangeably? Thanks
'umumnya' & 'biasanya' are interchangeable in the example sentence.
I'm not sure if they are always interchangeable, because the base words have slightly different meanings.
'umum' = public, general, common.
'biasa' = usual, regular, common.
If you look up the KBBI definition of 'biasa' (see below), then you'll see that 'umum' is considered to be a synonym.
1 lazim; umum:
bagi masyarakat sekarang memakai sepatu sudah --;
But I'm sure that the base words are not 100% interchangeable.
'Toilet umum' (Public toilet).
'Toilet biasa' <== this doesn't work, it's not a synonym.