Sempre que quiseres pernoitar, a casa é tua.
Whenever you want to stay overnight, the house is yours.
Breakdown of Sempre que quiseres pernoitar, a casa é tua.
ser
to be
a casa
the house
teu
your (informal)
querer
to want
Questions & Answers about Sempre que quiseres pernoitar, a casa é tua.
Why is quiseres in the future subjunctive here?
The phrase sempre que (whenever) triggers the future subjunctive when talking about a hypothetical or future event. Since we do not know exactly when or if you will want to stay overnight, we use the future subjunctive quiseres instead of the present indicative queres.
Could I use the indicative after sempre que in a different context?
Yes! If you are talking about a repeated habit in the present or past, you use the indicative. For example, if you said Sempre que queres pernoitar... (using the present indicative), it would mean 'Whenever you usually want to stay overnight...' describing an ongoing, established routine rather than a hypothetical future possibility.
Where does the irregular form quiseres come from?
It is the tu form of the verb querer in the future subjunctive. For irregular verbs, the future subjunctive is built from the third-person plural of the simple past tense: eles quiseram. Drop the -am to get the base quiser-, and add the tu ending -es to get quiseres.
Why does the second half of the sentence use the present tense (é) if the first half refers to the future?