It looks like it would literally translate as:
Nó khong phải là cố tình
I thought "khong phải là" was how to express "to not be"?
As far as I understand "là" is skipped if there is no object following it but only an adjective.
Yes I'd think 'nó không phải.." might also be acceptable. Mods?
Maybe since "cố tình" is a verb in Vietnamese, you cannot treat it as a noun like that.
I tried that answer too and was marked wrong.
I wrote nó không phải cố tình. My vietnamese friend told me it should be accepted but it was not.
get your act together