You would continue trying to speak the language of man; specifically English; for the rest of your days. Sometimes desparately trying to voice at least the simplest of words, like "mom" or "dad," or even "I". Words that even babies could utter.
Other times, you forget you are unable to speak. Those times would always catch you off-guard and bring back to reality of what you are; and those times would then turn into the times where you desparately attempt to say what you should have said instead of "hee haaww" that caught you off-guard and back to reality I the first place. When you are "brought back to reality," it's because you were either daydreaming about your former human life, or actually sleep-dreaming about your former human life. Either way, accidently thinking certain words that are unable to slip through your donkey-shaped vocal chords because it slipped your mind what species you are stuck as, would always bring you back to reality: that your nothing but a fucking donkey. A dirty fucking donkey. A dirty, smelly fucking donkey. Whose entire diet consists mainly of grass and dry hay. Who must shove his face into those unappealing vegetables, rather than use hands and fingers like a properly civilized human would. Unable to do that, because you have no hands or fingers with which to bring to grab your food and to your mouth. You are stuck with completely inflexible, blocky hooves, whose only purpose is to support your much heavier donkey frame. And so, you're stuck with shoving your large, oversized snout into your food like the uncivilized donkey you are.
And sometimes, when you think of a body part as "yours," you catch yourself, and think "that snout isn't even mine!" Or "these hooves aren't mine!" Or "these teeth and this tongue aren't mine!" It was really awkward when you would think of your tail as "YOUR" tail! And this would begin to both gross you out, and make you feel trapped. Almost the same feeling you'd imagine it would be like to be buried alive, or turned to stone. Your trapped with the body of a natural-born jackass, and you have no hands or fingers! Your mind would simultaneously drift to what you SHOULD be doing. What the donkey you switched with is probably doing with your life, instead of you. While you are doing what that donkey should be doing with this life.
And so, you would inevitably try to "break out" your fingers. But donkey hooves can't so much as flex, even the slightest bit. It was almost like having hands that were permantly frozen in stone. Trying to move and "feel" your fingers would always be a most uncomfortable experience. And sometimes, you desparately try to use your fingers and talk at the same time. Trying to will your "spirit" or "essences" or whatever out of your dirty, four-legged, gray-furred prison. But you can't do that. You are well and truly stuck.
When these things happen, you would unwittingly become horny. Your large, black, donkey-sized and donkey-shaped penis would go completely erect. You would always try and use your left-front hoof to grip it with your non-existent hand and Jack off with it. This would cause you to become even more erect. Your frustration would build. You'd then also try to speak. To ask for help. Anything. But your "hee hhaawwiing" would fall on uncomprehending ears. All you are to the world, is a braying jackass, and that's all you'll ever be.
The inability to speak would build your frustration even more, which would make your penis begin to pump up and down on its own. Slapping you on your white-furred belly. The only creatures in existence that would be aware of your need and desire; at your physical bodily need and desire rather than your mental need and desire; are other members of the species you have become. Specifically, females of your new assigned species.
A female would catch a scent of your need to procreate that is exuded from your donkey body through no choice of your own. And since you have been granted the instincts of a donkey, your physical needs would outweigh your logical mental capacity. You'd unwittingly walk towards the female and begin sniffing her well-used natural-born, slimy black cunt that other natural-born male donkeys have already mounted. And to your human mind that is forced to go along for the ride, the smell is always HORRENDOUS. It would make you completely hot and horny like you've never been before. This would always shock your mind as you attempt to resist. But your body's natural instinctual need to procreate, always over rides your human protesting mind.
Youd mount the female, and your donkey dick would nail the mark like so many other donkey dicks before yours have done. As your forelegs dangle over her sides, you try to flex your fingers to get a grip on her sides, and launch yourself off of the nasty furry beast. But you have no fingers, and you have no control over your body at these times. You try to scream your protest, but your body just naturally brays out a lustful "hhee hhaaw hhhee Hhhaaww hhhee Hhhaaww" over and over again as you hump her. Both donkeys, the one you're forever trapped as, and the female you are forced to experience donkey sex with, begin to sweat. While you are so mounted and so noisy, you are always extremely self-conscious, and even more utterly humiliated. Afterwards, you always feel extremely ashamed, grossed out, violated, suffer from the intensely strong memories of what is utterly foreign to your human brain. But you're completely unable to ever escape your new life.
It would also be disconcerting to you that donkeys have no need for communication, other than the smells that exude out of their bodies that then drives their simple-minded brains. They just simply have an overwhelming desire to have sex. The only donkey on the entire planet with a human mind, is you. That's it. As a former member of one of the 7 billion people on this planet, you are one-of-a-kind. And not in a good way. Your stuck living out the life that the donkey with your body should be living. And experiencing everything that donkey should be experiencing.
After having sex, your body would then have the need to replenish itself. And so, you'd be stuck mowing the lawn for quite a while. You'd just be one more member of your herd to be outside grazing, and you'd be at it for hours. Munching on grass, turning it into a green slimy mash before being forced to swallow the stuff. Then your head would dip down for more. These are the times where your human mind would drift off into Neverland. Where you are an actual human. Where you can use computers, drive cars, and own dogs as pets. It would always take you quite a while before you'd realize your body was finished nourishing itself, and so, you'd just stand there stupidly, with your large, dull brown eyes being vacant of all intelligence to any outside human observer. Sometimes, you'd stand there for hours, not even noticing it, as your mind plays the it's human episodes like a movie. You would truly, and utterly be engrossed by your day dreams, that you completely forget about your real station in life.
Sometimes, it would be a person, like your owner, that would snap you out of your intense reverie. Sometimes, it's your first brays, as you are so engross with the images your brain is projecting, that you actually begin to speak....ATTEMPT to speak.....in real life. Of course, it would come out as a harsh "heeee hhaaww." And so, the images in your brain would disappear, to be replaced by your near-sighted donkey vision with it's washed-out greens, blues, and grays. And all would come crashing down again as you are reintroduced to your donkey body like the very first time on that fateful day when you blinked you are suddenly and immediately looking out of the large dark eyes of your new home, and standing on four legs with a boxy furry body.