Watch more Child Development Stages videos: http://www.howcast.com/videos/513298-Age-6-and-Age-7-Developmental-Delay-Signs-Child-Development
Some signs that your six or seven year old may be developmentally delayed could include, if you're not able to understand what they are saying, or they're not able to follow directions.
Another thing to note would be if they're unable to hold a pencil, or if it's difficult for them to hold a pencil, that could be a cause for concern.
If they're clumsy, or unable to keep up with their peers outside in the playground that could be a cause for concern.
If they're withdrawn, if they're not wanting to engage with their peers, or engage with you, that's cause for concern.
If they ever lose a skill that they once had, that's also cause for concern.
What's important to know is that anytime you feel that something maybe off, and you have that gut reaction, and there's an instinct that " something might be off with my child," don't delay. Speak with your child's pediatrician, and share with him or her your concerns for your child's development, and they will tell you whether or not there's cause for concern.