couldn't arrive also be muncul ? she we appears/ showed up... because datang to me sounds like when we came, which I guess also works ...
'arrive' = 'tiba' , 'datang'
'muncul' has a different meaning than 'tiba' or 'datang'.
ok so are you saying muncal means appears not arrive?
Yes. muncul = to appear, to show up (to let yourself be seen), to emerge.
Sedang tidur OR lagi tidur.
why is kita wrong? surely this could be inclusive also
It's not wrong.
For this example, I put 'Kucing itu sedang tidur ketika kami datang'. I know that there aren't really 'cases' but is it more common to omit the 'sedang' for past tense? Or is that only added if the listener shows confusion?
In this sentence, you can use 'sedang', but you can also leave it out, it doesn't change the meaning.
Is 'bila' Malay?
Pada masa or pada waktu ought to be accepted instead of ketika here