insupportable

In a sentence

• Ce bruit est insupportable.

  This noise is unbearable.

  Here, "insupportable" conveys that the noise is annoying or intolerable.

• Trois heures dans la file d'attente, c'était insupportable.

  Three hours in the queue was insufferable.

  In this case, "insupportable" is used to describe the frustration or difficulty experienced in a situation.

• Il était tellement désagréable qu'il est devenu insupportable.

  He was so unpleasant that he became unbearable.

  Here, "insupportable" is used to characterize a person's behavior that has reached an intolerable level.