thanks for clarifying! it's a great help! <a class="adverts" style="text-decoration: none; color: #000000; font-weight: bold;" title="Get a cool boxed name @ weirdgenerator.com (OUT: 450)" href="http://www.weirdgenerator.com/" target="_blank">ツ</a>

<em>The two words are serving different purposes. The first is a helper to set the tense. The second is the main verb. See the following example.</em>

I have eaten too much for lunch.

(have = helper      eaten = main verb)

I had eaten too much for lunch before I went back to work.

(had = helper         eaten = main verb)

<em>But if I change the main verb from 'eat'  to 'have' you get the following:</em>

I have had too much for lunch.

(have = helper      had = main verb)

I had had too much for lunch before I went back to work.

(had = helper         had = main verb)