This week’s Sumerian sign is ĝeš, which means tree or wood. It’s an important sign that was used a lot.
ĝeš is one of a collection of signs that are written but not spoken as silent signifiers of a noun’s type or class. This sign often appears before objects made out of wood, like weapons or tools.
So in isolation, ĝeš would be pronounced, but if it came before another noun, it would probably be unspoken, meant only as a signal to the reader to help interpret the following sign, since many signs had multiple meanings and pronunciations.
There are a lot of signs that do this. There’s a sign that appears before gods’ names. There’s a sign that goes before birds or bugs (I think maybe the Sumerians classified flying insects as a kind of bird maybe?), a sign that goes before things made of stone, a sign that goes before people’s names, and many more. There’s also a sign that goes after place names.
When we transliterate these signs, we write them in a superscript to show that they’re silent. For instance, we’d write ĝešaš-te to mean (wooden) chair, even though in the original cuneiform the signs are all the same size.
The closest analogy to English writing, I guess, would be like using capital letters for proper nouns. It’s a way to signal something important to the reader.