I've been studying Welsh for a while. Welsh has a gazillion ways
to say yes or no, and you have to pick the right
one for the right circumstance. If someone asked me Wyt ti'n
hoffi cwrw? ("Do you like beer?") and I answered Naddo
("No" about a past-tense action) instead of Nac ydw
(literally "I am not"), I would have used the language incorrectly
but I daresay I would be understood. I'd just sound like an idiot.
You're right though, I might sound like an idiot. But maybe we all do when we speak Klingon? It's hard to tell what a Real Klingon would think (but It Is interesting to think about).
"Although a good many of the fine points are not covered, the sketch will allow the student of Klingon to figure out what a Klingon is saying and to respond in an intelligible, though somewhat brutish, manner. Most Klingons will never know the difference." — The Klingon Dictionary