Below, is a pdf file of a chart that lists all the sounds we have in the English language. The left side of the bar indicates when a child starts to say the sound (on average),and the right side of the bar shows when most children can say the sound, or as speech-language pathologists say, mastered the sound.
It is important to remember that when a child learns to talk, he or she may not say all of his or her sounds correctly. This is very normal, and it is expected by most speech-language pathologists. However, if a child has many incorrect speech productions and is not easily understood at age three or after, then it's recommended that he or she be evaluated by a speech-language pathologist.
So, what can you do as a parent to help your child's articulation? First, if you have any concerns at all, please seek the help of a licensed and certified speech-language pathologist. Since articulation therapy is so structured, I think it’s best targeted in a therapeutic environment. You can also find some simple tips and more information by reading 3 Tips to Target Your Toddler's Articulation.
To learn easy and practical speech and language tips to help your toddler talk and communicate faster, be sure to check out my book on Amazon Kindle, Talking With Toddlers - 52 Tips to Boost Speech and Language Skills.