Is it normal that my 7 month old baby is still not sitting up or crawling he grabs everything and i put him on the floor but when i do he screams cry?

Gross Motor Dev: Gross motor development ( six months) : sits with support, transfers object from one hand to other; rolls over back to front and front to back. Sitting without support may take place between 7 months- 9 months ! inability to sit by 9 month of age is abnormal.

Try putting him : in prone on a quilt. Put a toy just out of reach in front of him, then move it side-to-side. . He should hold his head & chest up steadily with weight on both forearms, then shift his weight to one while reaching for & attaining a toy with the other. When placed in a sit, he should maintain a "tripod ", flexed at the waist & propped on both hands. GE Reflux can cause discomfort in prone.