english ! tenses

<p>does anyone have a gd link or know how to explain the weird tenses?
i mean the perfect ones present and past when to use had and when to just use the simple past cos those are the things that are stopping me from getting what im aiming for on the writing section..</p>

<p>Kinda long but... <a href="http://www.englishpage.com/verbpage/verbtenseintro.html%5B/url%5D"&gt;http://www.englishpage.com/verbpage/verbtenseintro.html&lt;/a&gt;&lt;/p>