Language
The first place is occupied by the most ancient and often used method of information transfer. Without language there would be nothing. People simply could not understand each other, as it was many thousands of years ago, when humanity was still at the first stages of its development. Today there are thousands of languages with dozens of dialects in each. Most of them are no longer used, many are used in remote corners of the world by various tribes. Thanks to the language we understand each other, thanks to him we develop as a civilization and thanks to him you can learn about the 12 most important inventions of man!
He attended school last year. He didn't go to school last year
They went to London last week. When did they leave for London?