Breastfed babies do not need to have complementary food introduced until about the middle of the first year. Before that time, you will notice some signs that your baby is changing developmentally, in preparation for beginning solids in a few months. You will notice that:
he becomes more sociable, playing and holding "conversations" with you during a nursing session
he has a growth spurt and nurses more frequently for a while
he imitates the chewing motions you make whilst eating -- he is practicing!
You will know that he is really ready to start solids when:
he is about six months old
he can sit up without any support
he continues to be hungry despite more frequent nursing which is unrelated to illness or teething
he has lost the tongue-thrusting reflex and does not push solids out of his mouth
he can pick up things with his finger and thumb (pincer grasp)
Babies who are ready for solids can usually feed themselves. Mothers often report that they knew their babies were ready when they picked up food from a plate, chewed it, swallowed it, and wanted more.
Listen to your baby! Babies with a tendency to allergies may refuse solids until later in their first year. As long as they are growing well and are happy and healthy, there is no need for concern.