"Combien de temps avant que cela ne soit votre tour ?"

Translation: How long before it is your turn?

[juandenil]

What's with the ' ne' ?

[Sitesurf]

It is called "ne explétif", meaning that it is used for the flow of words but does not mean the sentence is negative.
to know more: http://french.about.com/od/grammar/a/negation_form_2.htm

[gbv9900]

What is the reasoning, if any, behing using one of the most important words in any language purely for rhythm, rather than using a meaningless noise instead?

"How long before it is your turn" is a neutral sentence.

[tiny_tam]

"avant que" is one the constructs that gets followed by a "ne explétif" - see the link Sitesurf gave above.

[juandenil]

Thank you for that.

[tomhudd]

Much clearer, thanks.

[GrafRandi]

This sentence could easily be: 'until it's your turn' in English, it should be accepted too

[Bartleby]

Why ”cela” and not ”ce”?

[Sitesurf]

Both are correct.

[slickster]

""How much time until it's your turn?"" -- is that a different sentence in French? e.g. "Combien de temps jusqu'à ce qu'il soit votre tour?"

[Sitesurf]

The only variant I can think of is: "combien de temps avant que ce soit votre tour ?"

"avant qu'il soit" does not work and an impersonal sentence.

[noxfarm01]

I took the safe bet and translated this as, "How much time before it is your turn?" but I really wanted to try, "How much time before this is your tower'?" Is the latter translation valid?

[Sitesurf]

A bit stretched, isn't it?

But yes, "un tour" and "une tour" cannot be distinguished if the owner is "nous" (notre), "vous" (votre) or "ils/elles" (leur)

[Hemanttsha]

..dear Sitesurf, your contribution is...simply beyond words..

[sfgsfg1]

Not for me!

[RobinDietr]

Could "tour" not also mean tower? Like "how long until that tower is yours"?