JSFiddle - React, Tailwind, and code Playground

HTML

<div id="nav">
            <ul class="main_menu">
                <li><a href="#">Home</a></li>
                <li class="trigger">
                    <a href="#">Hypotheken</a>
                    <ul class="sub_menu">
                        <li><a href="#">Hypotheekvormen</a></li>
                        <li><a href="#">Hyporheek rente</a></li>
                        <li><a href="#">Nationale hypotheek garantie</a></li>   
                    </ul>
                    <div class="clear"></div>                       
                </li>
                <li><a href="#">Verzekeringen</a></li>
                <li class="trigger">
                    <a href="#">Downloads</a>
                    <ul class="sub_menu">
                        <li><a href="#">Hypotheekvormen</a></li>
                        <li><a href="#">Hyporheek rente</a></li>
                        <li><a href="#">Nationale hypotheek garantie</a></li>   
                    </ul>
                </li>
                <li><a href="#">Contact</a></li>
            </ul>
        </div><!-- nav -->

JavaScript

$(document).ready(function () { 

        $('.sub_menu').hide(); //hiding the element

        $('.trigger').mouseenter(function() {
            $(this).children('.sub_menu').slideDown(350); 
        }).mouseleave(function() {
            $(this).children('.sub_menu').slideUp(350); 
        });   
});