When asking 'What is your name?' or 'What is your job?', why is it 'は' not 'か'?


As per the title, when asking 'What is your name?' or 'What is your job?', why
is it 'は' not 'か'? For example, we are taught this:

> おしごとは。  
>  'What is your job?'

But I don't understand why it isn't this?

> あなたはしごとですか。  
>  'What is your job?'




お仕事は？ _Oshigoto wa?_ is basically short for お仕事は何ですか？ _Oshigoto wa nan desu
ka?_

あなたは仕事ですか？ _Anata wa shigoto desu ka?_ means "Are you work?" and is
nonsensical†.

は _wa_ (not わ BTW) is the topic marker.* Just asking 〜は basically means "About
~..." and only hints at the actual question. Leaving things unspoken is a very
typical thing in Japanese. _"About (your) work..."_ is the subtle, polite way
to ask "What is your work?".

Simply 仕事か？ _Shigoto ka?_ would mean something like "Work, eh?" and is more of
an exclamation than a question. It's also rather rough, at the very least _not
polite_.

* * *

* That's why あなたは仕事ですか？ _Anata wa shigoto desu ka?_ marks "you" as the topic and is wrong. It's basically saying _"About you, are you work?"_

† In the context of this question at least, see comments.




お仕事は？ _Oshigoto wa?_ is basically short for お仕事は何ですか？ _Oshigoto wa nan desu
ka?_

あなたは仕事ですか？ _Anata wa shigoto desu ka?_ means "Are you work?" and is
nonsensical†.

は _wa_ (not わ BTW) is the topic marker.* Just asking 〜は basically means "About
~..." and only hints at the actual question. Leaving things unspoken is a very
typical thing in Japanese. _"About (your) work..."_ is the subtle, polite way
to ask "What is your work?".

Simply 仕事か？ _Shigoto ka?_ would mean something like "Work, eh?" and is more of
an exclamation than a question. It's also rather rough, at the very least _not
polite_.

* * *

* That's why あなたは仕事ですか？ _Anata wa shigoto desu ka?_ marks "you" as the topic and is wrong. It's basically saying _"About you, are you work?"_

† In the context of this question at least, see comments.

