Breakdown of Se a matrícula estiver completa, eu passo a preocupar-me menos com o início do curso.
Questions & Answers about Se a matrícula estiver completa, eu passo a preocupar-me menos com o início do curso.
Because se here introduces a future condition: if the enrolment/registration is complete at some later point.
In Portuguese, when se means if and refers to something uncertain in the future, the verb normally goes in the future subjunctive.
That is why you get:
- Se a matrícula estiver completa... = If the registration is complete / once the registration is complete...
Here, estiver is the future subjunctive of estar.
Using está here would sound non-standard in careful Portuguese for this kind of future condition.