Question in the topic-title. Sorry if I post in the wrong part of the forum.

Best regards,

Jan.

Mi volas ke vi faru ....

But with peti, two structures are possible.

Mi petas vin fari

Mi petas ke vi faru

sudanglo:Mi volas ke vi faru ....

But with peti, two structures are possible.

Mi petas vin fari

Mi petas ke vi faru

Why can't you also say "Mi volas vin fari?"

Rejsi:

sudanglo:Mi volas ke vi faru ....

But with peti, two structures are possible.

Mi petas vin fari

Mi petas ke vi faru

Why can't you also say "Mi volas vin fari?"

Because you don't want someone. You want something from them but you can ask someone to do something.

sudanglo:Mi volas ke vi faru ....

But with peti, two structures are possible.

Mi petas vin fari

Mi petas ke vi faru

Sudanglo, I notice that you do not insert a comma before the "ke." The lingvohelpilo continually reminds me to do so. Is there a preferred way?

To hop onto that question, why always put a comma before ke? That always seemed odd to me.

coderiferous:To hop onto that question, why always put a comma before ke? That always seemed odd to me.

David Jordan in his guide to Esperanto attributes it to influence from European languages, but doesn't specify which ones.

David Jordan:Except in the phrase por ke = “in order that,” it is conventional to put a comma before ke or ĉu. I know of no reason for this, although it is done in some European languages. The comma contributes nothing to the sentence, and its use seems to be decreasing, but many editors still regard it as an error or an Anglicism if you leave it out.

I've always been under the impression that German uses a comma before its equivalent of ke, but I myself don't know German and would like to be told if I'm right or wrong about that.

etala:

David Jordan:Except in the phrase por ke = “in order that,” it is conventional to put a comma before ke or ĉu. I know of no reason for this, although it is done in some European languages. The comma contributes nothing to the sentence, and its use seems to be decreasing, but many editors still regard it as an error or an Anglicism if you leave it out.

I've always been under the impression that German uses a comma before its equivalent of ke, but I myself don't know German and would like to be told if I'm right or wrong about that.

You are right about that.
And for me it's quite natural to use a coma here, because there is always a small pause:
I know, that you ...
Mi scias, ke vi ...
Ich weiß, dass du ...

horsto:

etala:
I've always been under the impression that German uses a comma before its equivalent of ke, but I myself don't know German and would like to be told if I'm right or wrong about that.

You are right about that.
And for me it's quite natural to use a coma here, because there is always a small pause:
I know, that you ...
Mi scias, ke vi ...
Ich weiß, dass du ...

See...that's always been weird to me. In English, there is no pause in the phrase "I know that you..." But alas, it's convention in Esperanto. So I follow along.

coderiferous:To hop onto that question, why always put a comma before ke? That always seemed odd to me.

In Esperanto commas seperate clauses of a sentence. Notice that each clause can have own subject, verb and object. Thus they don't refer to another clause and relation beetwen clauses is expressed by words like ke, tiu, tiam.
And why?
Because it is more transparent and many other languages do the same, for example Polish.