Re-posting the following checklist I posted in a previous page:
Here's a guide given by the dev ped of my sons:
Expressive language milestones:
1 year - 1 word sentences
2 years - 2 word sentences
3 years - 3 to 5 word sentences
4 years - 4 to 7 word sentences
Expressive vocabulary:
1 year - 1-10 words
1 1/2 years - 10-100 words
2 years - 100-250 words
2 1/2 years - 250-400 words
3 years - 450-900 words
4 years - 1500+ words
Speech milestones:
3 years - sounds of the letters m, b, p, h, w and all vowels
4 years - k, g, t, d, n, ng, f
5 years - s, z, l, v, y, th, sh, wh, ch
6 years - r, j
Speech intelligibility (how well others understand your child)
2 years - 25%
2 1/2 years - 60-65%
3 years - 75-90%
4 years - 90%
Source: Kathleen E. Mahn, Vanderbilt Universtiy,
www.forepath.org* Stuttering in the preschool years is normal. Be sure to give your child time to say what he is trying to say.
*** If you have concerns about your child's speech and language skills, discuss it with your child's doctor or a speech-language pathologist.
Other resources:
www.asha.org,
www.stutteringhelp.org