usen

In a sentence

• A les escoles, generalment, usen llapis per escriure.

  In schools, they generally use pencils to write.

  Here, 'usen' is used as the third person plural present tense of the verb 'usar', meaning 'they use'.

• Els científics usen microscopis per estudiar cèl·lules.

  Scientists use microscopes to study cells.

  In this sentence, 'usen' continues to represent 'they use' and refers to the action by scientists.

• Quan llegeixen, usen ulleres per veure millor.

  When they read, they use glasses to see better.

  Again, 'usen' is utilized to mean 'they use', highlighting its flexibility in describing various actions by different subjects.