Speaking and writing comes instinctively to us. In contrast, speaking about language is complex because the production of language requires multiple processes, both in our brains and the external environment. This process probably started half a million years ago when our distant ancestors first uttered discrete sounds to convey meanings. 
But speech per se is ephemeral. A spoken word shuttles between the private space of the mind and the public space of conversation and is quickly “lost”. It wasn’t until much later (around 3,000 BC) did we start to leave traces of thoughts on our physical world – on clay tablets, stone slabs and animal bones. That moment was an epiphany; whereas spoken words fade quickly from consciousness, written down, however, they endure and become the bedrock of culture.
The earliest writings were done on cuneiform clay tablets that date to around 3,000 BC. This early form of writing was invented by the Sumerians who lived in major cities with centralised economies in what is now southern Iraq. Temple officials needed to keep records of the grain, sheep and cattle entering or leaving their stores and farms and it became impossible to rely on memory. So, an alternative method was required and the very earliest texts were pictures of things that scribes needed to record. Appropriately, these writings were known as pictographs. The texts were drawn on damp clay tablets using a pointed tool. After some time, the Sumerians began to draw marks in the clay to make up signs, which were standardized so they could be recognized by many people. This was an important step in the evolution of writing. Cuneiform writing died out eventually; the latest known example is an astronomical text from AD 75.
Writing in Egypt started at about the same time as the Sumerians, two centuries before the start of the First Dynasty. The most well-known script used for writing the Egyptian language was in the form of a series of small signs, or hieroglyphs. Some of these signs are pictures of real-world objects, while others are representations of spoken sounds. Like cuneiform, Egyptian hieroglyphs were used for record-keeping. They were also used also for monumental display dedicated to royalty and deities. The word hieroglyph carries this meaning; it comes from the Greek hieros for ‘sacred’ and gluptien meaning ‘carved in stone’.
The earliest writings in China were oracles dating to the Shang Dynasty (about 1500-1050 BC) with its capital at Anyang. Shang kings believed their ancestors could advise them and would discern these oracles by reading patterns of cracks on turtle shells or polished oxen shoulder blades. The cracks were in fact man-made, produced by applying hot rods on the oxen shoulder blades or turtle shells. Scribes would carve questions and answers into these ‘oracle’ bones, asking for instance, about the best time to grow crops. Unlike cuneiform and Egyptian hieroglyphs, the Chinese script did not die out but underwent centuries of major changes as they evolved into later Chinese scripts that are still in use today.
 Tecumesh Fitch, “More than Just Small Talk: Seeking the Roots of Human Language within the Tree of Life”, in Shuzhen Sim and Benjamin Seet (eds), The Chronicles of Evolution, Wildtype Books, 2019