dur

In a sentence

• Ce n'est pas facile de découper ce métal, il est vraiment dur.

  It's not easy to cut this metal, it is really hard.

  Here, 'dur' is used to describe the physical hardness of the metal.

• Le temps était dur pour eux pendant cette période difficile.

  Times were hard for them during this tough period.

  In this sentence, 'dur' is used metaphorically to describe a challenging situation.

• Cette chaise est inconfortable car le siège est trop dur.

  This chair is uncomfortable because the seat is too hard.

  Here, 'dur' denotes the physical firmness causing discomfort.