Final answer:
The phrase 'I crossed my fingers' is an idiom that expresses a hope for good luck or a desirable outcome, and is not meant to be taken literally.
Step-by-step explanation:
The phrase 'I crossed my fingers' is an example of an idiom. An idiom is a figure of speech where the words, when taken together, have a different meaning from the literal interpretation of the individual words. In this case, 'crossing one's fingers' is an idiomatic expression that means hoping for good luck or for a favorable outcome. It does not literally mean that the person needs to cross their fingers but rather is wishing strongly that something happens the way they want.