It is normal for a toddler to say tuck instead of truck or yeyo instead of yellow. However, children should transition to proper pronunciation of words by the time they start school. Yet it is dangerous to simply wait for things to get better if you suspect your child is having speech problems. The sooner they learn how to speak better, the smoother their social interactions are and the less likely it is their speech problems affect their education. Conversely, parents don’t want to cart their child to a doctor only to be told their mispronunciations are normal for this age.
This is where WPS Publish, a leader in medical, research and academic publishing that specializes in autism, speech, language, occupational therapy and school psychology comes in. They’ve created a straightforward infographic for your reference. It names the most common phonological errors. It states when it should go away and when it indicates a problem that needs to be addressed immediately.