1. Physical development standards for nine-month-old babies. At nine months, the baby\’s body has made great progress in all aspects. They may already be able to sit up and balance, or even try crawling or standing. Additionally, they may begin to use their fingers to pinch or grasp objects. 2. Language development standards for nine-month-old babies In terms of language, a nine-month-old baby may begin to imitate your speech, and will try its best to imitate the words and tones you speak. They may also be able to pronounce simple syllables