Don't vs Can't
shì是1
bù不2
wéi为3
yě也4
，
fēi非5
bù不6
néng能7
It is that you will not do it, not that you cannot.
1. это (было) (this, it [demonstrative pronoun])
2-3. неделание
4. final sentence particle [marking judgment/clause break]
5. а не (is not, it is not that [negation in nominal predicate])
6-7. неспособность (inability)