Incapable (adjective)

1. Not having the ability, means, or qualifications to do something.
2. Unable to do something.

Origin:

From french incapable, from in- ("not") + capable ("capabl.e")

Examples:

1. He was deemed incapable of handling the job.
2. She was incapable of making a decision.
3. The machine was incapable of performing the task.
4. He was found to be emotionally incapable of continuing.
5. The company is financially incapable of making the investment.