What did you eat today?

[MrApple]

Hello everyone. I am trying to learn Japanese on my own. I bought the Genki textbook, and am now in lesson 4... still such a long way to go but we'll get there eventually

I wanted to ask my (non-Japanese) friend what she ate today, and tried to with my current limited knowledge. Does this make any sense gramatically? :
今日は何を食べましたか。

I'm quite sure it doesn't, but maybe some one can help me with a better translation.

Thanks.

[TJack]

The sentence is absolutely correct and you can use that structure to ask any what questions like

何を読みましたか。
What did you read?
何を見ましたか。
What did you watch/see?

And you can give a reply by replacing 何　with any noun like

りんごを食べました。
I ate an apple.

[chikara]

.... I wanted to ask my (non-Japanese) friend what she ate today, and tried to with my current limited knowledge. Does this make any sense gramatically? :
今日は何を食べましたか。......

The use of the は topic marker after 今日 makes 今日 the topic of the sentence so you are asking "What was eaten today?". The emphasis is on "today". By the context of the conversation you friend may take that to mean what did they eat today but it sounds unnatural, to me at least. While the particle に is used to indicate a specific time relative times such as "today" don't take the に particle.

You could simply say;
今日何を食べましたか。

[MrApple]

Thank you TJack and chikara.

@Chikara -
Hmm you are right. I wanted to put the emphasis on what was eaten, not when it was eaten. Does that make sense?

Thanks for the feedback