Two of my sons were speech delayed. Second son (now DS12) had a "0" articulation score at about 2.5 yrs or 3 diagnostics but was perfect on nonverbal score (equivalent to 6 yr old). We put him in speech therapy and he started really talking about 3.5-4, but had an impediment. He had therapy again in grade school and it was corrected pretty quickly.

Fourth son also was delayed and started speech at about 2.5. We were not as concerned because of older brother's experience. He has a more pronounced impediment and will likely be in speech therapy through elementary school.

Other 2 sons started speaking around 10 months and have no impediments. Isn't that weird?