When you assert something you believe, use the ordinary present (crec que és car). But after a negated opinion or an expression of doubt, need or importance, switch to the present subjunctive: -ar verbs take -i (parli), -er/-ir verbs take -i too (begui, dormi), with irregulars like sigui, tingui, pugui.
Examples
- No crec que sigui una bona idea.
- I don't think it's a good idea.
- És important que la gent hi participi.
- It's important that people take part in it.
- Dubto que el metro arribi a temps.
- I doubt the metro will arrive on time.
- Crec que el lloguer és massa car.
- I think the rent is too expensive.
The mistake to avoid
Crec que takes the normal present; only the negative No crec que triggers the subjunctive.
Where this fits in
Ciutat, societat i opinions, Catalan B1: Get around the city, discuss society, and express opinions.