* Prefixes often DO change meaning: A prefix typically adds a new layer of meaning to the base word. For example, "un-" in "unhappy" makes the word the opposite of "happy".
* Prefixes can change pronunciation: Even if the core meaning remains similar, the prefix can change how the word is pronounced. Think of "pre-empt" vs. "empt."
However, here are some words or phrases you could use:
* Unaffected: This suggests the prefix doesn't alter the core meaning or sense of the word.
* Invariant: This is a more formal term implying the word remains unchanged in its fundamental nature, despite the prefix.
* Unmodified: This emphasizes the lack of alteration to the base word.
* Not altered: This is a straightforward, simple way to convey the idea.
Example:
"The prefix 're-' in 'reiterate' doesn't significantly alter the meaning of the word 'iterate,' but it does add a sense of repetition."
Ultimately, the best term to use will depend on the specific context and the nuance you want to convey.