usar

In a sentence

• Yo uso un lápiz para escribir.

  I use a pencil to write.

  In this sentence, 'uso' is the first-person singular present tense of 'usar', meaning 'I use.' It denotes the act of utilizing a pencil as an instrument for writing.

• Ellos usan zapatos cómodos.

  They wear comfortable shoes.

  Here, 'usan' is the third-person plural present tense form, meaning 'They use,' which in this context implies that they wear comfortable shoes, hence indirectly using them for practicality.

• ¿Sabes cómo usar esta máquina?

  Do you know how to use this machine?

  The word 'usar' in this question remains in its infinitive form and denotes the act of operating the machine, placed after the auxiliary verb 'saber' (to know).