Grammar Comparison

Spanish Future: Ir a vs Simple Future

Master the subtle differences between "voy a hacerlo" and "lo haré". Compare plans, predictions, commitments, and learn how to use the future tense to make guesses about the present.

1. The Central Difference

Spanish has two primary ways to express future actions. They often translate to "going to" and "will" in English, but the rules are not exactly the same.

Ir a + Infinitive

Voy a hacerlo. I am going to do it.

Simple Future

Lo haré. I will do it.

In many situations, both forms are perfectly correct. The choice often depends on how you want to present the action: as an intention, a promise, or a prediction.

2. Four Major Contrasts

A. Plan/Intention vs. Future Statement

Voy a estudiar esta noche. I am going to study tonight.
A planned intention. You already have it in your schedule or mind.
Estudiaré esta noche. I will study tonight.
A future statement or prediction. Often sounds slightly more formal or neutral.

B. Prediction based on Evidence vs. General Prediction

Mira esas nubes. Va a llover. Look at those clouds. It's going to rain.
A prediction based on what we see right now. The event feels imminent.
Mañana lloverá. It will rain tomorrow.
A general prediction about the future, like a weather forecast.

C. Intention vs. Commitment

Voy a llamar a María esta tarde. I am going to call María this afternoon.
A statement of your plan.
No te preocupes. La llamaré mañana. Don't worry. I will call her tomorrow.
A commitment, promise, or reassurance to someone else.

🤯 The Future That Isn't About the Future

One of the most valuable features of the Spanish simple future is that it can express probability or conjecture about the present.

Where is he?

¿Dónde está Juan? Estará en casa. He is probably at home.

It does NOT mean "He will be at home later." It is a guess about right now.

What time is it?

¿Qué hora será? Serán las ocho. It's probably around eight o'clock.

A highly natural textbook example of wondering about the present time.

3. The Secret Connection: Haber & Future Endings

The auxiliary verb haber helps explain the historical logic behind the Simple Future endings. If you know the present tense of haber, the future endings are exactly the same!

Subject Haber (Present Tense) Futuro Simple Example (Hablar)
Yo he hablaré (I will speak)
has hablarás (You will speak)
Él/Ella/Ud. ha hablará (He/She will speak)
Nosotros hemos hablaremos (We will speak)
Vosotros habéis hablaréis (You all will speak)
Ellos/Uds. han hablarán (They will speak)
Whenever you forget or feel uncomfortable with the endings in the simple future, just remember the simple past tense auxiliary verbs (present perfect), i.e., he, has, ha, hemos, habéis, han.

4. Pronoun Placement (Crucial)

Simple Future

When using the Simple Future, the pronoun ALWAYS goes before the conjugated verb. It is never attached to the end.

Te ayudaré.
Se lo diré.

Ir a + Infinitive (2 Options)

With the "Ir a" structure, you have two options: place the pronoun before the conjugated verb, or attach it directly to the infinitive.

Te voy a ayudar.
Voy a ayudarte.
Se lo voy a decir.
Voy a decírselo.

5. The 12 Irregular Future Stems

Ir a + Infinitive

Completely regular! The main verb is always in the infinitive form. There are absolutely no irregular verbs to memorize here.

Simple Future

All verbs use the exact same future endings, but there are 12 common verbs that change their stem.

tener
tendr-
tendré (I will have)
hacer
har-
haré (I will do)
decir
dir-
diré (I will say)
poder
podr-
podré (I will be able to)
poner
pondr-
pondré (I will put)
salir
saldr-
saldré (I will leave)
venir
vendr-
vendré (I will come)
saber
sabr-
sabré (I will know)
querer
querr-
querré (I will want)
haber
habr-
habrá (There will be)
valer
valdr-
valdrá (It will be worth)
caber
cabr-
cabré (I will fit)

🟠 10 Very Common Sentences with IR + A

These are cases where ir a + infinitive sounds particularly natural in everyday speech.

SpanishEnglishWhy it works
Voy a ser padre.I'm going to be a father.personal plan / imminent life event
Voy a llamarte luego.I'm going to call you later.everyday intention
Voy a hacerlo ahora.I'm going to do it now.immediate intention
¿Qué vas a hacer mañana?What are you going to do tomorrow?asking about plans
¿Vas a venir con nosotros?Are you going to come with us?asking about intention
Voy a salir un momento.I'm going out for a moment.immediate action
Vamos a comer.We're going to eat.immediate/intended action
Voy a dormir.I'm going to sleep.immediate intention
Mira, se va a caer.Look, it's going to fall.prediction based on present evidence
Va a llover.It's going to rain.immediate/evidence-based prediction

⭐ Particularly useful ones

¿Qué vas a hacer?

This is much more natural in everyday conversation than the formal-sounding ¿Qué harás? when simply asking someone about their plans.

¿Vas a venir?

Extremely useful conversational Spanish.

Voy a hacerlo.

One of the most useful future constructions to master.

🔵 10 Sentences Strongly Associated with the Simple Future

Here we deliberately choose expressions where the simple future has a special pragmatic meaning or is much more idiomatic.

SpanishEnglishFunction
Ya lo verás.You'll see.reassurance / prediction
Algún día entenderás.One day you'll understand.prediction
Será un honor.It will be an honor.formal/polite expression
Serás un buen padre.You'll be a good father.prediction / reassurance
Ya veremos.We'll see.uncertainty / postponing judgment
No te preocupes, todo saldrá bien.Don't worry, everything will be fine.reassurance
Lo haré.I'll do it.promise / commitment
Nunca lo olvidaré.I'll never forget it.strong commitment/emotion
¿Qué será?I wonder what it is.conjecture
Estará en casa.He's probably at home.present probability

Summary: How to Choose

🟠 IR + A

What are you going to do?

  • Voy a estudiar.
    I'm going to study.
  • ¿Qué vas a hacer?
    What are you going to do?
  • Mira, va a caer.
    Look, it's going to fall.
Think:
intention · plan · expected/imminent event · evidence

🔵 SIMPLE FUTURE

What do you think / promise / predict?

  • Ya lo verás. / Lo haré.
    You'll see. / I'll do it.
  • Será un honor.
    It will be an honor.
  • Estará en casa.
    He's probably at home.
Think:
prediction · promise · reassurance · formal statement · probability

Continue Studying

Deep Dive into Irregular Stems: