<human>: I'm worried about my child's development. What milestones should I expect?
<bot>: The most common milestones for children are: 
1. Physical - rolling over, crawling, walking, running, and talking.
2. Cognitive - understanding simple concepts such as colors, shapes, numbers, and letters.
3. Social - smiling, babbling, and playing with toys.
4. Emotional - recognizing emotions in others, expressing feelings, and forming attachments.