Here's what we know:
* Pictographic symbols: The Sumerians likely started with pictographs, simple drawings representing objects or ideas. This is a common development in early writing systems.
* Clay tokens: Archeological evidence suggests they used clay tokens shaped like various objects. These tokens may have been used for record keeping or accounting. It's theorized that these tokens eventually became the basis for pictograms.
* Early signs: Some scholars believe that the Sumerians used a system of early signs on clay tablets, possibly representing syllables or sounds, before the fully developed cuneiform. These early signs were more complex and abstract than simple pictograms.
Key points to remember:
* Limited evidence: We have very limited evidence of the Sumerians' pre-cuneiform system. Most of our understanding comes from analyzing the development of cuneiform itself.
* Debate among scholars: There's still debate about the exact nature and evolution of pre-cuneiform writing.
In summary: While we don't know for sure how the Sumerians communicated before cuneiform, it's likely that they used a system of pictographs, clay tokens, and early signs that gradually evolved into the sophisticated cuneiform system we know today.