Expressing Conditions with "desde que"
To say "provided that" or "as long as" in Portuguese, use the conjunction desde que. We use this phrase to set a condition that must be met for something else to happen.
| provided that | desde que |
Whenever you use desde que to talk about a condition in the present or future, the verb that immediately follows it MUST be in the Present Subjunctive.
Applying "desde que"
Let's look at some common rules for using a local spa (o spa). For regular verbs, the Present Subjunctive typically swaps the vowel endings: -ar verbs take -e endings, while -er and -ir verbs take -a endings. For example, usar (to use) becomes uses.
| The shower is mandatory before entering, provided that you use the sauna. | O duche é obrigatório antes de entrar, desde que uses a sauna. |
Many common verbs have irregular subjunctive stems. Notice how trazer (to bring) becomes tragas, and ir (to go) becomes vás.
| You can use the spa, provided that you bring the flip-flops. | Podes usar o spa, desde que tragas os chinelos. |
| The swimming cap is mandatory in the spa, provided that you go to the pool. | A touca é obrigatória no spa, desde que vás à piscina. |
More Subjunctive Forms
Here are a few more highly irregular subjunctive forms you will encounter when stating conditions:
- estar (to be) becomes esteja
- haver (to exist / there to be) becomes haja
- fazer (to do / make) becomes faça / faças
Let's see these in action with some rules about the changing room (o balneário), the locker (o cacifo), and getting a massage (a massagem).
| You must leave the clothes in the changing room, provided that the locker is empty. | Deves deixar a roupa no balneário, desde que o cacifo esteja vazio. |
| One relaxes a lot here, provided that there is silence in the sauna. | Relaxa-se muito aqui, desde que haja silêncio na sauna. |
| You must relax, as long as you do the massage today. | Deves relaxar, desde que faças a massagem hoje. |