The opposite of becoming able is becoming helpless or incompetent. This means that instead of gaining proficiency, there is a loss of ability or aptitude. Examples of antonyms for becoming able include losing the ability to walk, becoming immobile, losing the ability to speak, becoming mute, and becoming less skilled or less efficient in performing tasks. Other antonyms for becoming able are becoming incapacitated, disabled, or impaired. These antonyms highlight the negative impact of losing ability and the importance of maintaining and developing skills and competencies. Overall, the antonyms for becoming able emphasize the stark contrast between gaining proficiency and losing it.