Prefixes:
* Un-: This prefix negates the meaning, creating "unobstruct," meaning "not obstructed."
* Re-: This prefix indicates repetition or renewal, creating "reobstruct," meaning "to obstruct again."
Suffixes:
* -ion: This suffix forms a noun, creating "obstruction," meaning "the act of obstructing."
* -ive: This suffix forms an adjective, creating "obstructive," meaning "tending to obstruct."
Therefore, "obstruct" is a versatile word that can be modified to create new words with different meanings.