Present perfect = has written

The present perfect is used to describe an action that began in the past and that is continuing into the present. It is usually used in conjunction with the words for and since, which serve as “tip-offs” that this tense is required.

Correct: Leslie Marmon Silko has written best-selling novels since 1977.

Correct: Leslie Marmon Silko has written best-selling novels for more than thirty years.

Although these sentences describe actions that began in the past, they both clearly imply that that Leslie Marmon Silko is *still* a best-selling author.

 

Simple past = wrote

The simple past is used to describe an action that began and ended in the past.

Correct: Leslie Marmon Silko wrote her first best-selling novel in 1977.

OR

Correct: Leslie Marmon Silko was twenty-nine years old when she published her first novel.

On the SAT, sentences that require the simple past typically include a date or time period that clearly indicates a past action or event (e.g. 1815, The Renaissance, etc.).

 

Past perfect = had written

This is the tense that people tend to have the hardest time with. It is used only in the following case: when you have two finished actions in the past, the past perfect is used to describe the one that happened first.

In other words, if a sentence does not clearly indicate two separate actions, you should not use the past perfect!

Correct: Before Leslie Marmon Silko published her first best-selling novel in 1977, she had already written a number of well-regarded short stories.

Action #1: Leslie Marmon Silko published a number of well-regarded short stories.

Action #2: Leslie Marmon Silko wrote her first best-selling novel in 1977.

The past perfect is therefore used to describe the first action.

Under no circumstances is the following correct:

Incorrect: Before Leslie Marmon Silko had published her first best-selling novel in 1977, she wrote a number of well-regarded short stories.