<em>(noun)</em> An infinitive is the basic form of a verb without an inflection binding it to a particular subject or tense (ex: to see, to walk, let him see)
<em>(</em><em>adjec</em><em>tive</em><em>)</em><em> </em>having or involving an infinitive form (ex: infinitive clauses)
It gives a clearer picture of what is going on,which helps the reader able to imagine what is going on in the story since the Diary of a Wimpy Kid are a little wordy.