You are reluctant to write an extra credit book report because you are afraid that your language and punctuation skills are not good enough. which function of a word processor will convince you to try it?

 Spell check  

Spell check is a very useful tool available in the word processor application.

Explanation:

It checks and verifies certain aspects like spelling, grammar, punctuation's etc.

When the user type a text in the word processor application, when there is a spelling error, the word automatically shows those in red, if there is a grammatical error then it underlines the text in green, similar way for the punctuation including the capitalization of the Starting letter after each line.

So this spell check function will be very helpful to do these literary aspects.