Translating the sentence, we get something along the lines of Raul ____ the pen to write. There's one word we can see falls into the blank, and that's used. Now all wee need to do is translate used into Spanish. One way to say used in Spanish is usado, so usado is the word that best completes the sentence.
They recieve a special hat
<span>There are certain Spanish verbs that require a specific preposition to be used after them. These prepositions must follow the verb form to join them to an infinitive, but they are usually not translated into English.
</span>
