Conditions with gerunds (-ando, -iendo)

You don't always need si (if) to state a condition. Instead, you can start a sentence with a gerund.

Spanish gerunds are the equivalent of English "-ing" verbs, ending in -ando (for -ar verbs) or -iendo (for -er and -ir verbs). Placing a gerund clause at the beginning of a sentence sets up a condition, often translating to "If you..." or "By...".

If you grow the cactus indoors, you use less water.
Cultivando el cactus en el interior, usas menos agua.
If you use the spray bottle every day, you keep the fern beautiful.
Usando el rociador todos los días, mantienes el helecho hermoso.

Giving Instructions and Advice

You can pair a conditional gerund with a command to give specific instructions.

If you care for an orchid, always spray it with the spray bottle.
Cuidando una orquídea, pulverízala siempre con el rociador.
If you see a rotten stem, cut it immediately.
Viendo un tallo podrido, córtalo inmediatamente.

You can also pair the condition with an impersonal se structure to share general advice.

If you take a cutting from the succulent, another plant is obtained.
Sacando un esqueje de la suculenta, se obtiene otra planta.

Warnings and Consequences

This structure is also useful for warning someone about negative consequences.

If you water the orchid too much, you damage the plant.
Regando la orquídea demasiado, dañas la planta.
Watering the orchid too much, the root usually rots.
Regando la orquídea demasiado, la raíz suele pudrirse.