incompetent

US /ɪnˈkɑːm.pə.t̬ənt/
UK /ɪnˈkɑːm.pə.t̬ənt/
1.

bất tài

not having the ability to do something as it should be done:

:
an incompetent teacher/doctor
1.

bất tài

someone who does not have the ability or skill to do something as it should be done:

:
The country's being governed by a bunch of incompetents.