'Able' in the Bible

And [Ish-Bosheth] was no longer able to {answer} Abner {because he feared him}.

But now he [is] dead. Why [should I be] fasting? [Am] I able to return him again? I [am] going to him, but he cannot return to me."

Now Jonathan and Ahimaaz [were] staying at En Rogel, so a servant girl used to go and tell them, then they would go and tell King David, for they [were] not able to be seen coming to the city.