Lisa Friedman, Inclusive Educator, Religious School Director, teacher, writer & parent
There really isn't so much of a "typical timeline" as there is a range. No two children develop at the same pace. Your pediatrician will certainly be looking for specific milestones and developmental markers as your child grows. A red flag, however, is if your child regresses; meaning he or she acquires certain skills and then stops demonstrating them. Language falls into this category. Acquiring words and forming sentences followed by a lack of speech or significant reduction in speech is a developmental red flag. So, too, is a child who crawls, pulls up and walks and then regresses to only crawling. In general, if you have a gut sense that something isn't quite right, talk to your pediatrician. There are also terrific parenting books to give you a sense of such suggested timelines like the "What to Expect" series, but again, recognize that these are general suggestions and all children develop differently.