Have doctor evaluate
At 6 months of age, one can try giving the baby some baby cereal (prepared with water or formula
If the baby is able to move the cereal around in his mouth, and swallow most of it, they he is ready for solid baby foods. If the baby seems to keep sticking his tongue forward and push the cereal out, then he should practice off and on for 2-3 more weeks. If still unsuccessful, see the doctor.