In Bookworm each mage ('real' mages, not just people with magic power) is granted a magical item by the Gods that can change its form into various magical tools through certain specific phrases.
During a class, Myne casually wonder if she can transform it into something else, and she did it with a registered keyword "Mizuteppou" (the toy water gun)
Her initial version shoot out water that has cleansing effect, but then later on while lazing in her room she wondered if she can shoot something else, like how her teacher shot multiple crossbow bolts from a single shot of his magical crossbow.
So she tried, and got scolded for wrecking her room in doing so.
Later on she also make a spell 'copy then paste' that do just that, copying texts and replicating it to another spot.
Though after she got over her initial excitement she realized she got 'copy and paste' wrong, so now the spell is forever 'copy then paste'
She even give it the ability to adjust the text size on the fly later on.
Ferdinand "Look, your text is the wrong size here, this is fine for normal texts but won't work for magic circles"
Myne "Hmm, let me try to see if I can resize it"
Fer "What absurd thing ar-"
Myne "I did it!"
Fer /facepalm "...right, just keep going then"