“Humans are weird” idea
It seems to always be the case that aliens have names that are “unpronounceable by the human tongue.” But, y’know, humans are actually really good mimics. We can do impressions of anything, and some of us are really good at it. What if that was a special skill of ours that was constantly surprising the aliens?
Alien talks about human like s/he’s not there, only to be shocked when its own language comes out of that strange little mouth.
Alien can’t figure out WHAT that noise onboard is, only to find human crewmate pranking it. (“As soon as he leaves, I’m gonna do the sound of a failing hover engine, okay? Just see where he looks first!”)
Alien hears a different noise and a thud, then “Sorry, I tripped.” (”But you squeaked.” “Yeah, didn’t mean to. Sounded kinda dumb.”)
Alien is alarmed to hear the sound of two Dangerous Animals coming from the containment room. Thinks the one has multiplied. Runs in, find human yowling back at it. (“It seemed lonely, so I was talking to it. Reminds me of a cat I had once.”)
The away team is threatened by a Large Animal protecting its young. Alien Captain knows what to do. Shoves the human up front and points. “Make the noises that the little ones are making. This is your time to shine.”