Read it like this: The spelling of a word may <u>change</u> as the plural is formed. Does the sentence make sense? Yes, and here is an example.
STUDENT is singular, while STUDENTS is plural. It doesn't have a different meaning, but the spelling just changes because of the "s" you added.
Hope this helps!
Nora thinks about leaving her own family which builds suspense
It uses a cloak, it's the answer because that's what a vampire squid looks like