I can say what will happen under what condition: Si llueve, no iremos a la playa — and I won't use the future tense after si.
What will happen if…
Real condition: si + present → futuro
This is how you talk about a real condition: what will happen if something happens. Si llueve, no saldremos.
One structure: after si comes the present tense, and the main part takes the future tense (futuro). The condition is always in the present, the result in the future.
English works the same way: “If it rains, we'll stay home” has the present after “if”. So after si there is never a future tense: NOT “Si lloverá” — correct: Si llueve.
The order of the parts is free, but the comma is needed only when the si part comes first: Si mañana hace frío, iremos al museo = Iremos al museo si mañana hace frío (no comma).
The condition can be negative too: Si no te das prisa, llegarás tarde.
The familiar entonces picks up the result: ¿Llueve? Entonces cogeremos un taxi. And por si acaso means “just in case”: what you do in advance, in case the condition comes true: Coge el paraguas por si acaso.
Common mistakes:
• NOT “Si tendrás dinero, comprarás el coche” — correct: Si tienes dinero, comprarás el coche.
• NOT “Si hará calor, abriremos las ventanas” — correct: Si hace calor, abriremos las ventanas.
• NOT “Cogeremos un taxi, si llueve” — the comma is not needed here: Cogeremos un taxi si llueve.
• NOT “Coge el paraguas en caso” — correct: Coge el paraguas por si acaso.
Real condition: two parts
The condition is always in the present tense, the result in the future tense (futuro). The parts can go in either order, but you need a comma only when the si part comes first.
| Condition — present tense | Result — futuro |
|---|---|
| Si llueve, | no saldremos de casa. |
| Si mañana hace frío, | iremos al museo. |
| Si Jorge viene, | haremos una excursión. |
Lesson notes
Real condition: si + present → futuro
This is how you talk about a real condition: what will happen if something happens. Si llueve, no saldremos.
One structure: after si comes the present tense, and the main part takes the future tense (futuro). The condition is always in the present, the result in the future.
English works the same way: “If it rains, we'll stay home” has the present after “if”. So after si there is never a future tense: NOT “Si lloverá” — correct: Si llueve.
The order of the parts is free, but the comma is needed only when the si part comes first: Si mañana hace frío, iremos al museo = Iremos al museo si mañana hace frío (no comma).
The condition can be negative too: Si no te das prisa, llegarás tarde.
The familiar entonces picks up the result: ¿Llueve? Entonces cogeremos un taxi. And por si acaso means “just in case”: what you do in advance, in case the condition comes true: Coge el paraguas por si acaso.
Common mistakes:
• NOT “Si tendrás dinero, comprarás el coche” — correct: Si tienes dinero, comprarás el coche.
• NOT “Si hará calor, abriremos las ventanas” — correct: Si hace calor, abriremos las ventanas.
• NOT “Cogeremos un taxi, si llueve” — the comma is not needed here: Cogeremos un taxi si llueve.
• NOT “Coge el paraguas en caso” — correct: Coge el paraguas por si acaso.