JSFiddle - React, Tailwind, and code Playground
HTML
<input type="text" onkeydown="removeSpecials(this)"/>
JavaScript
var patt = /^[a-zA-Z]*$/;
patt.test("The best things in life are free!");
var currentInputValue = "";
function removeSpecial(e) {
var patt = /^[a-zA-Z]*$/;
if(patt.test(element.value)) {
currentInputValue = element.value;
}
}