The Grammar Acquisition Lab studies how and when children develop particular aspects of language called syntax and morphology. We are interested in the learning processes of children with speech and language difficulties, as well as the way that typically developing children learn morpho-syntax. We hope that by understanding more about the development of morpho-syntax, we will gain insights into which factors, like processing capacity and linguistic structure, might influence language use in both typically developing children and children with speech and language difficulties. This knowledge may allow us to develop more sensitive assessment instruments and more effective interventions for use with children with speech and language difficulties.
Specific
Projects Underway 
Production
of Complex Sentences:
We are currently conducting a project that looks at how children put together
complex sentences (Think of sentences that have two parts, like Ernie
wanted/Elmo to go to the store or Ernie thought/that Elmo went
to the store). We are interested in finding out what children know
about producing the second part of these types of sentences. We are also
interested in finding out what strategies children use to put sentences
with two parts together. Finally, we want to know if the type of verbs
or the length of the sentence affects whether children say the sentence
correctly.
We do this by having children watch several short puppet shows and then tell us what they see. The kids get a chance to talk to Ratty (who is too shy to watch) or Sleepy Bear (he just can't stay awake through the puppet shows) in addition to the lab staff.
In
addition to puppet shows, kids get to play a hiding and finding game,
repeat silly words, and look at lots of picture books. Sometimes we also
just spend a few minutes playing on the floor or reading a book together.
We need both children with speech and language
difficulties and typically developing children to participate in our studies.
Results
of current projects
We are just getting started here at The University of Iowa, so it will
be a little while before we have current results to show you. In previous
projects conducted at Purdue
University, we found out that children with SLI have more difficulty
producing complex sentences than typically developing children do. Sometimes
they leave out function words, like that or to and other
times they don't mark the verb correctly. Rarely, they leave out important
content words in a sentence. Both children with SLI and typically developing
children seem to have more problems with sentences like Ernie remembered
that Elmo wore a hat than with sentences like Ernie remembered
to wear a hat. This doesn't seem to be related to how long or short
the sentence is, but we can't quite be sure of that - future projects
will have to study that question in more detail.