To supplant someone is to replace them with someone else, usually because the latter is more powerful or better in some way.
A supplicant is someone who humbly and respectfully asks for something from another who is powerful enough to grant the request.
When you supplement, you add on some extra to something to make up for a lack in it.
When something is suppressed, it is blocked from occurring or kept contained in some way.
When you support someone, you help them do something or agree with what they are doing.
ask humbly (for something)
give something useful or necessary to
express a supposition
Differentiated vocabulary for your students is just a click away.