The history of technology teaches us that every non-trivial problem -- and a large fraction of trivial problems -- require specification beyond the bounds of conversational language.

Greek geometers may have invented the idea of formalizing language with specific definitions, and inventing new symbols to represent special meanings. When important consequences accrue from getting things wrong, people develop jargon: knitters and sailors and shepherds and farmers; engineers and lawyers and plumbers. If you want to convey your knowledge and intentions, you can't chat informally and expect a human to really understand what you want.

For about a century now we've had devices that turn instructions into actions. Everyone who uses these becomes an expert in the particular form of instructions that the device needs, or else they don't get what they want.