Answer:
Unless
Step-by-step explanation:
A conjunction is a word that joins two independent clauses together. Independent clauses are clauses that can stand on their own as complete sentences.
For the Question:
The conjunction in the sentence "You will not succeed unless you work harder" is "unless".
The word "unless" joins the two independent clauses "You will not succeed" and "you work harder" together.
Therefore, Conjunction is unless
