Verb Conjugation using "keiner von beiden"

Question

When you conjugate a verb for use with the pronoun beide, you use the 3. Plural.

Beide brauchen geld

But what happens in case we use keiner von beiden instead?

I did a google exact text search, and I found a lot of examples using the 1. Singular, but also 3. Singular.

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Some Examples found:

• Keiner von beiden muss schnaufen.
• Ich denke, keiner von beiden braucht dieses Zimmer.
• Keiner von beiden hat recht.

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I find it hard to locate examples with keiner von beiden used with the 3. Plural, so I believe it is used with either the 1. Singular or 3. Singular but I have not yet been able to track down some information on the topic about it.

So to compare two examples of usage I found on the internet against how I would write it:

• Ich denke, keiner von beiden braucht dieses Zimmer.
• Keiner von beiden muss schnaufen.
  
  Versus
  
  
• Ich denke, keiner von beiden brauchen dieses Zimmer.
• Keiner von beiden müssen schnaufen.

What is the correct conjugation when using keiner von beiden?

Answer 1

The pronoun "kein-" as a subject is always treated as singular 3. person, never plural and never 1. or 2. person.

This doesn't change for "keiner/keine/keines von beiden", which is not different from English "none of both is" (although it is "none of them are" for some reason none of us understands, or understand)

However, when "kein" is used attributively as a determiner of a noun in the subject, the verb is of course conjugated in agreement with the number of the noun:

In diese Kneipe gehen keine Touristen.
In diese Kneipe geht kein Tourist.

Answer 2

Keiner is the 3. person singular:

Keiner von ihnen/ beiden hat ...

It is the same in English:

No one of both has ... None of them has ...

Answer 3

Kein isn't a verb, so it isn't conjugated but declined. That is why things like "1st person" or "3rd person" don't make sense at all.

The tricky thing which may have confused you is articles (and kein follows this pattern) exist in all genders. (It seems to confuse English speakers to think that is "because of 3rd person singular", as it's the only place where English makes a difference between genders.)

           Einzahl                 Mehrzahl
           m       w       s
Nominativ  keiner  keine   kein    keine
Genitiv    keines  keiner  keines  keiner 
Dativ      keinem  keiner  keinem  keinen
Akkusativ  keinen  keine   kein    keine

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So, your question has to be rephrased. I think it boils down to singular vs. plural. If you can speak English, this isn't scary at all.

Beide brauchen Geld.

Both need money.

Obviously these are two entities, because of beide. So the verb has to be in plural. As in English.

Keiner braucht Geld.

No one needs money.

It's no one. Singular. As in English.

Now a tricky example:

Keiner von beiden braucht Geld.

Neither of both needs money.

Tricky? No, it's the same as in English. Singular.

Hier sind keine Leute.

There are no people here.

Plural. Same as in English.

Hier ist keiner.

There is no one here.

And again, singular. Same as in English.