It’s great that your three year old can understand what you are saying! By age three an average toddler’s speaking vocabulary is over 200 words and they often can string together two to three words into sentences. I suggest speaking about your concerns to your child’s pediatrician who can best assess your child’s hearing, speech, and language development and recommend any necessary interventions. Early speech interventions may not only help your child’s speech but may also help with reading success later in life.