With a mighty effort, baby can raise his chest, supported by his arms, when he lies on his stomach. He reaches for objects. Baby can put some weight on his legs when you hold him upright. Baby laughs out loud. He squeals when he's happy.
Baby smiles spontaneously.
He can focus on very small objects. Baby turns toward the sound of a familiar voice. All babies have their own internal developmental timetable. If you have concerns about your baby's development discuss them with his doctor. Because your baby's nervous system is maturing as well, his internal clock is becoming better regulated.