Improve
A four letter word meaning the foundation of something is base.
sqw
A ten letter word for something that occurs could be an occurrence or happenings.
have
The four-letter word that means "inside of" is "within." It is commonly used to indicate something contained or enclosed by something else.
Urge
One answer could be "chair" (hair, air).
A five-letter word that means "maybe" is "might."
An Acrostic
shard
have
lose