letras solo de entrada HTML
<!--To stop input from accepting numbers-->
<input onkeypress="return /[a-z]/i.test(event.key)" >
Ugliest Unicorn
<!--To stop input from accepting numbers-->
<input onkeypress="return /[a-z]/i.test(event.key)" >
<input type="text" name="Phone Number" pattern="[7-9]{1}[0-9]{9}"
title="Phone number with 7-9 and remaing 9 digit with 0-9">
<input type="text" pattern="[a-zA-Z'-'\s]*">