Real conditional clauses (si)

To talk about real possibilities and their predictable results—like what to do when a computer acts up—use si (if).

if
si

For likely scenarios, use si followed by the present tense, and use the present tense again for the result.

If the program is slow, I restart the system.
Si el programa está lento, reinicio el sistema.
If you press the red button, you turn on the screen.
Si presionas el botón rojo, enciendes la pantalla.

Giving instructions with "hay que"

When giving general troubleshooting advice, it is common to pair a si clause with hay que (one must / you have to).

If the system freezes, you have to restart the computer.
Si el sistema se bloquea, hay que reiniciar la computadora.
If the keyboard is dirty, you have to turn off the computer.
Si el teclado está sucio, hay que apagar la computadora.

Reflexive verbs

Pay attention to reflexive verbs like bloquearse (to freeze). Remember to place the reflexive pronoun directly before the conjugated verb.

to freeze (computers, devices)
bloquearse
If the screen freezes, the teacher presses the button.
Si la pantalla se bloquea, el profesor presiona el botón.