Learn French: Je vous demande de ne pas ouvrir la cage.

When negating an infinitive verb like ouvrir, both parts of the negative (ne pas, ne jamais, ne plus) stay together. They are placed directly before the infinitive. If the verb were conjugated, the negative would wrap around it like vous n'ouvrez pas, but with an infinitive, it is always ne pas ouvrir.

Why do we need the word de before ne pas ouvrir?

In French, the verb demander requires the preposition de when it is followed by another action. The complete structure is demander à quelqu'un de faire quelque chose (to ask someone to do something). The negative block ne pas simply slips in right after the de.

Is vous a direct or indirect object in this sentence?

It is an indirect object. Because the verb phrase is demander à quelqu'un, the vous here essentially means 'to you.' This is important to remember if you want to talk about a third person: to say 'I ask him' or 'I ask her,' you must use the indirect pronoun lui, making it je lui demande.

Could I use the verb poser instead of demander to mean 'ask' in this sentence?