I have been designing resources for many years as I worked with preschool and primary age youngsters with delayed or impaired speech and language skills. The resources using symbols are free. My latest resources which I have illustrated are extra tasks based on Marion Blank's Language Levels (previous ones have been free). They can be used with groups of mixed language ability and are reasonably priced.
Symbols (c) Widgit Software 2010. Eight pages with an action picture and 3 symbols to stand for Subject-Verb-Object. ‘Symbol reading’ can be an excellent way to prompt children with delayed language skills to string more words together in the correct order. Accept any efforts at a word for each symbol without correction or asking for the child to copy you. However you can give praise and confirm the effort by saying back the simplest grammatical version of the child’s effort.