I always wondered why Ax never 'caught on', so to speak.
I can understand the initial problems of human morph, as well as blending into human society, but still, after years of living among humans, don't you think he would have gotten over saying words over again such as things like, "buns..bun-zuh", etc.
He's an advanced, educated life form, aware early on of the existence of other intelligent species. Also is the threat of attack. After the first few times of flipping out over food, and being yelled at by the other Animorphs, don't you think he would quit it, for the sake of not getting controllers suspicious?
It can't that uncontrollable; Visser Three is completely fine in human morph, as were many of the other Andalites shown in the story at one point or another, such as Gafinilan. Granted, Ax is young and may have less self control, but after years of assimilation and far closer contact with humans than any of the other Andalites that have been on Earth, I'm pretty sure he should have been capable of passing as a normal human. I'm sure he wouldn't be versed in all of human culture, such as historical things like older TV shows or catchphrases, or understanding the more complex aspects of human humor, but things as late as the famous line from book #49 shouldn't have happened.
"Ah." Ax nodded. "She does not understand
how menacing we are." He tapped her on the
shoulder. "You do not know me," he said, "but I
am a juvenile delinquent. I do not trust authority
figures, I probably will not graduate from high
school, and statistics say my present rowdiness
and vandalism will likely lead to more serious
crimes. I am a dangerous fellow, and I am causing
mayhem in this store."
He reached behind her and pulled three jars
of baby food from the top shelf. Shoved them behind
a box of macaroni. Shuffled the Cheez Whiz
in front of the Marshmallow Fluff. Tossed a bag
of lady's shavers onto a bag of hamburger buns.
"There. I have now shamelessly destroyed the
symmetry of this shelf, undoing hours of labor by
underpaid store employees. If you could see me,
you would be frightened."
I mean, come on. That late in the series, he should have been fully aware the average human does not talk like that.
It just bothers me they treat Ax as a nerdy burden. Great in a fight and full of information, yet a bumbling idiot in society. I can't blame him early on; it's an alien civilization! But he is capable of complete understanding of the language, and lives in proximity to many humans who are trying to educate him. He should have made at least some significant progress by the end, beyond being able to tell when Marco is being sarcastic.