incapable
adj.adj. not having the ability or strength to do something. You use this when someone cannot perform a task or lacks a specific skill.
adj. lacking the necessary ability, power, or fitness to perform a specific action. Often followed by the preposition 'of' and a gerund.
He is incapable of lying to his friends.
The old computer was incapable of running the latest software because its processor was too slow.
Despite his extensive training, the pilot found himself momentarily incapable of reacting to the sudden mechanical failure, paralyzed by the sheer scale of the emergency.
Borrowed from Middle French incapable, equivalent to in- + capable.
Typically followed by the preposition 'of' and a noun or a verb ending in -ing.
incapable to do itincapable of doing itIncapable is followed by 'of' and a gerund, not a 'to' infinitive.