Uninflected word

An uninflected word is a word that doesn't change its form no matter what. Imagine you have a puppy, and you call the puppy's name, "Max!" Even if you shout, "MAX!" or whisper, "Max," the name stays the same. That's like an uninflected word - it doesn't change no matter what you do.
For example, the word "dog" is uninflected. It doesn't matter if you are talking about one dog or many dogs, the word stays the same. You don't add any letters or change it in any way. It's always just "dog."
So, when talking about uninflected words, just remember that they are like your puppy's name - they always stay the same, no matter how you use them.