Usage of か after verbs


In the following sentence

> 今日は何の映画を見るか決めたの

what is the grammatical role of か?




From your comment it seems you are asking about the difference between:

>   1. 今日は何の映画を見るか決めた  
>  Today I decided on which film I will watch.
>   2. 今日は何の映画を見ること(を)決めた  
>  ????
>

In 1) 何の映画を見るか (which film will I watch) is an embedded question. The whole
phrase behaves like a noun, which can take the optional object particle を. So
the basic structure is

> 今日はXを決めた  
>  Today I decided on X

where X is "what film I will watch".

I don't believe sentence 2) is grammatical because of the question part 何の in
it. You could say:

> 今日は映画を見ることを決めた  
>  I decided on watching a film

but that is a different structure with a different meaning.




From your comment it seems you are asking about the difference between:

>   1. 今日は何の映画を見るか決めた  
>  Today I decided on which film I will watch.
>   2. 今日は何の映画を見ること(を)決めた  
>  ????
>

In 1) 何の映画を見るか (which film will I watch) is an embedded question. The whole
phrase behaves like a noun, which can take the optional object particle を. So
the basic structure is

> 今日はXを決めた  
>  Today I decided on X

where X is "what film I will watch".

I don't believe sentence 2) is grammatical because of the question part 何の in
it. You could say:

> 今日は映画を見ることを決めた  
>  I decided on watching a film

but that is a different structure with a different meaning.

