How Ordinary Words Evolve Into Grammar
The word will once meant to want or desire. Over centuries, languages stripped away its original meaning until it transformed into a mere tool for indicating the future tense.
This process is called grammaticalization, where concrete words like nouns or verbs morph into abstract grammatical markers. It is why many auxiliary words we use today started as descriptive verbs or objects long ago. You can think of it as a form of linguistic recycling where specific meanings fade to serve the structural needs of a sentence. It proves that our language is constantly shifting under our feet in ways we rarely notice.
Source: Grammaticalization