Spanish language Q&A Forum

Explain formal and informal

Hello, in another context, I have come across the expression: 
No le di la mano hasta que no supe su nombre.
Would it also be correct, and have the same meaning, to omit the second "no" ?
And, in the 3rd example on this page, could one also say: 
No vas a salir de casa hasta que no recojas tu habitación.
? 

thanks!

I am curious how this structure would work if the direct object is a pronoun, something like the following.

I had a beautiful beer mug.  I accidentally dropped it.

Can I opt out of using the vosotros form?

1. Yo no sabía que ellos ya conocían a nuestro sobrino. 

2. Yo no sabía lo que ellos ya conocían a nuestro sobrino.  

What it be if the sentence is "I didn't know what they already knew our nephew."

Thank you.

Por favor, enséñanos la pronunciación y la entonación correctas.

hi, why is this not considered subjunctive tense?