Change_Ownership.sol

// SPDX-License-Identifier: UNLICENSED
pragma solidity 0.8.11;


contract Onwership {
    address public owner;

    modifier onlyOwner {
        require(owner == msg.sender, "You are not the owner");
        _;
    }
    
    constructor() {
        owner = msg.sender;
    }

    function sayHello() public view returns (string memory) {
        if (msg.sender == owner) {
            return "Hello owner!";
        } else {
            return "Hello world!";
        }
    }
 
    function changeOwnership(address _newOwner) public onlyOwner returns (bool result) {
    // function changeOwnership(address _newOwner) public{
        require(owner == msg.sender, "You are not the owner");
        owner = _newOwner;
        return true;
    }
}