Past Participle in SAT writing section

<p>1) I am having so much trouble with past participles on the SATs. Do you use had when it happened before a previously stated action in the past?...I dont know if what I just said there even makes any sense.Simple put... Could someone explain to me when to use past participles on the SATs?</p>

<p>2) I am also having problems with "that". Sometimes it is used in the beginning of a sentence and it is not the error. Could someone explain to me why it isnt an error?</p>

<p>***Please help. Not knowing this always gets me a 46/49 on the writing. I really want to get it perfect to make up for what may turn out to be a 3/6 essay.</p>

<ol>
<li><p>I think you are asking about a specific kind of past participle called the past perfect when you refer to using had. Yes, the past perfect is used to describe an event in the past that occurred before another event in the past. Example: Elvis had left the building by the time I arrived at the concert. For some simple explanations of past participles go here: [Past</a> Participles in English - Grammar Rules Online](<a href=“http://www.grammar.cl/Notes/Past-Participles.htm]Past”>Past Participles in English - Grammar Rules) </p></li>
<li><p>“That” can be used at the beginning of a sentence to refer to something already mentioned. Example: Speaker 1: “You’re a liar.” Speaker 2: “That is not true.” That is thus referring to the accusation made.</p></li>
</ol>

<p>Ok I’ll look into the links. Thanks a lot</p>