funciona or funcione

Question

Would I say "un plan que funcione para usted" or "un plan personalizado que funciona para usted" ? I think the former, but my friend says the latter....

Answer 1

If there is a plan that you want to describe as a working one (in your opinion), use indicative (funciona).

If there could be a plan that may work, but you don't want to say whether it does work or not, use subjunctive (funcione). Actually, even if you think it works, but you don't want to say, use subjunctive anyway.