Hi,

I am finding very difficult to understand when and why you should use Subjuntivo form of verbs. I always feel that the Indicativo form can itself be used, dont feel the need of Subjuntivo..

Is there any site that will talk the basics of Subjuntivo?

Quiero que cierre la puerta.
(I want to close the door)

Cant I say
Quiero cerrar la puerta?

'Quiero que cierre la puerta' doesn't mean 'I want to close the door'. It means that you want another person (3rd person) to close the door (for example, "I want you to close the door.").
'Quiero cerrar la puerta' means 'I want to close the door'.

There are many reasons to use the subjunctive. Basically, if you're not dealing with facts (the real world), use the subjunctive. If your emotions are at play, use the subjunctive. When you want/desire/ask someone to do something, use the subjunctive. And there are certain phrases that trigger the subjunctive.

Do an internet search on +"Spanish" +"subjunctive" and you'll find plenty of resources. Don't exclude this site. MANY threads talk about the subjunctive mood.

The subjunctivo form of cerrar for (yo) and (él, ella, Ud) is "cierre".
Then how to make out 'Quiero que cierre la puerta' refers to a third person closing the door?
Can you pl help me understand?

Context tells us the person used. ;)

Maybe this link is helpful. In the first example you can see a similar sentence. :)