Funny how the brain works.

I'm correcting my students' latest batch of quizzes and came across this, which is really intriguing if you're a geek. And since I am, here it goes. One of the sentences required that they write "he laughed." My student clearly forgot the verb so she made one up, laetravit, taking the adjective for "happy," laetus, a, um, and combining it with the verb meaning "he barked," latravit. I don't know if she did this on purpose or if her head simply combined the two words, but it makes a lot of sense.