Sub-
An underground train, or, sandwiches.
What is a subway?
To put things together.
What is combine?
To move forward, as in water.
What is propel?
To make possible.
What is enable?
Sports, after the finals. (Post-)
What is the postseason?
Part of a set.
What is a subset?
An organization.
What is a company?
To put something forward, for instance, marriage.
What is propose?
To lift someone's spirits, with support.
What is encourage?
To come back, after some time. (Re-)
To reappear?
An underwater vehicle.
What is a submarine?
A friend, buddy, or partner.
What is a companion?
To keep under guard.
What is protect?
To give to someone, with respect.
What is entrust?
Cheap. (In-)
What is inexpensive?
An intermediate value.
What is a subtotal?
To push down or together.
Someone who gives.
What is a provider?
To make sure a rule is followed.
What is enforce?
Confusing, cryptic. (Mis-)
What is misleading?
To put underwater.
What is submerge?
A formal, impersonal honorific.
What is comrade?
To move forward.
What is progress?
To make bigger.
What is enlarge?
Those who came before us. (fore-)