I Watched My Grand Children This Past Week Total Of

I watched my grand children this past week total of three children 8,7,2 years old my youngest Grandson 2 years old can not speak only to nod his head no or slam his body on the ground to get his way. my youngest daughter said she was potty training him. when I tried he would not repeat anything only to hit himself in the face and try to move his left hand as if he was not getting out what he wanted with words i'm concerned grand parent