Learn Hardcore Portuguese (Portugal): Se descarregares a aplicação com Wi‑Fi, não gastas tantos dados. - If you download the app with Wi‑Fi, you don’t spend so much data.

It’s the future subjunctive, 2nd person singular (tu). Portuguese uses the future subjunctive after se to talk about real, open conditions that refer to the future. So Se descarregares… means “If/when you download (in the future) …”.

Why is the main clause não gastas in the present, not the future?

Portuguese often uses the present indicative in the result clause to express a general truth or habitual consequence, even when the condition refers to the future. You could say the future (não gastarás) or periphrastic future (não vais gastar), but the present (não gastas) is very idiomatic for a general rule.

Can I say Se descarregares…, não vais gastar tantos dados?

Yes. That’s also natural: future subjunctive in the if-clause plus periphrastic future in the main clause. It sounds a bit more predictive and less “timeless” than the present.

Where is the subject pronoun? Is this addressed to tu?

Yes. Portuguese is a null-subject language, so the pronoun is usually dropped. This sentence uses the tu forms: future subjunctive descarregares and present gastas. You could say Se tu descarregares…, não gastas…, but it’s not necessary.

How would I say it with você in European Portuguese?

Use third-person verb forms: Se você descarregar a aplicação com Wi‑Fi, não gasta tantos dados. In Portugal, você can sound formal or distant; tu is the default in most informal settings.

How might Brazilians say this?

Typical Brazilian version: Se você baixar o app no Wi‑Fi, você não gasta tantos dados. In Brazil, baixar and app/aplicativo are the norm, and no Wi‑Fi (“on Wi‑Fi”) is very common.

Is descarregar the normal verb for “to download” in Portugal? What about baixar?

In Portugal, descarregar and fazer download are very common and neutral. Baixar is widely understood and increasingly used, but traditionally it meant “to lower”. Avoid sacar in Portugal (there it means “to withdraw money”).

Why aplicação and not aplicativo or app?

In European Portuguese, aplicação is the standard word for a software application. Aplicativo is Brazilian usage. The borrowed app is also common in both varieties in informal contexts.

Why com Wi‑Fi? Could I say por/via/através de Wi‑Fi or no Wi‑Fi?

com Wi‑Fi = using Wi‑Fi (very natural in PT-PT)
por/via/através de Wi‑Fi = by/through Wi‑Fi (also fine)
no Wi‑Fi (“on Wi‑Fi”) is very common in Brazil; in Portugal it’s understood but less idiomatic than com/por/via.
Also, you may see the article: o Wi‑Fi (masculine).

What does gastar dados mean exactly? Why not usar?

Gastar means “to spend/consume,” so gastar dados emphasizes that your data allowance is being used up. Usar dados is acceptable but less precise about the idea of depleting a limited resource. Synonyms include consumir dados; the positive counterpart is poupar dados (“to save data”).

Why tantos dados and not tanto dados?

Tanto agrees in gender and number with the noun:

Masculine singular: tanto (tanto dinheiro)
Feminine singular: tanta (tanta bateria)
Masculine plural: tantos (tantos dados)
Feminine plural: tantas (tantas fotos)

Does dados here mean mobile data specifically?

Context decides. In tech/mobile contexts, dados usually means “mobile data.” You can make it explicit with dados móveis: não gastas tantos dados móveis.

Can I change the word order: Não gastas tantos dados se descarregares…?

Yes. Placing the se-clause first is common and usually takes a comma. If the se-clause comes second, the comma is often omitted: Não gastas tantos dados se descarregares a aplicação com Wi‑Fi.

What if I want a more hypothetical or unlikely condition?

Use the imperfect subjunctive in the if-clause and the conditional in the result:

Se descarregasses a aplicação com Wi‑Fi, não gastarias tantos dados.
This suggests an unreal/less likely scenario, unlike the original, which is a realistic condition.

Could I use quando instead of se?

You can, but it changes nuance:

Se descarregares… = if you download (conditional)
Quando descarregares… = when you download (temporal, you assume it will happen)

How is the future subjunctive (like descarregares) formed?

Start from the 3rd person plural of the simple past (pretérito perfeito): descarregaram. Remove -am to get the stem descarregar- and add endings:

eu/ele: descarregar
tu: descarregares
nós: descarregarmos
vós: descarregardes
eles: descarregarem

Why does the present subjunctive look different: descarregues vs descarregares?

Different moods. Present subjunctive is (que) tu descarregues. We insert gu to keep the hard g before e/i. In the future subjunctive descarregares, the g is before a, so it’s already hard and no u is needed.

Could descarregares also be a personal infinitive?

Yes, forms of the future subjunctive and the personal infinitive often coincide. With se, it’s the future subjunctive (Se descarregares…). With prepositions like para/ao/antes de, it would be the personal infinitive: para tu descarregares, ao descarregares.

Any quick pronunciation tips (European Portuguese)?

Approximate guide:

Se ≈ “suh”
descarregares ≈ “dsh-kah-heh-GAR-esh”
a aplicação ≈ “ah uh-plee-kah-SÃO”
com Wi‑Fi ≈ “kong why-fy” (you’ll also hear “wee-fy”)
não gastas tantos dados ≈ “now GASH-tash TUN-tush DA-dush”
Nasal vowels: não, aplicação, com, tantos. The final -s often sounds like “sh” in European Portuguese.