Fate - your destiny, cannot be altered. In the prologue, Shakespeare writes "A pair of star-cross'd lovers take their life" this is about Romeo and Juliet and it means that it's fate that they should not be together.

Free will - the power to act on ones own discretion. After Mercutio's death Romeo goes to Tybalt and says “Either thou or I, or both, must go with him." This shows free will because he chose to fight Tybalt, he did not have to.

Fate

Free Will