Speech is the hardest fine motor skill to achieve so it’s little wonder that it can take so long to master! There are error patterns that are common in English that our brain can cope with and understand, e.g. “loot at da tat!” (look at the cat). As a child gains more language and uses longer sentences, it can be increasingly hard to understand them if those error patterns continue.
There are also error patterns that can occur that are not a part of typical development and for these errors, it can be very hard to understand a child, e.g. leaving off the starting sounds in words “an I ave a ory” (Can I have a story?).
Typically children with speech difficulties use more than one error pattern at a time and when you combine all of the patterns, your brain has to work very hard to make sense of what you hear!
It’s not an expectation that parents will understand speech error patterns (it’s hard enough keeping up with feeding the kids right?!) but I do have parents/teachers interested in what sound patterns a child is using. Knowing a little about sound patterns can help you translate what your child might be saying (or writing) in a given word or sentence, and give you a better chance of understanding their message.
This is a great link for common speech error patterns that you might hear:
http://www.banterspeech.com.au/10-common-speech-error-patterns-seen-in-children-of-3-5-years-of-age/
If you are worried that your child has difficulty with speech, please contact me for an assessment.