Does "朝か晩に” as an expression exist?

Question

I am currently studying for JLPT N5 using Nihongo So-Matome, and one of the practice questions requires me to choose a sentence with a similar meaning to the one that is given, which is

たいてい宿題をしてから寝ますが、時々朝します。

Which i interpreted as

"Usually, I sleep after doing homework, sometimes I do it in the morning" 

This itself already sounds a bit wonky to me, but the answer given is

朝か晩に宿題をします

I'm not sure if か is a short for から here, but even if it is, the 2 sentences don't seem to share the same meaning? Is this a case of a bad translation from the textbook, or am I missing some basic grammar that is preventing me from understanding the sentence.

Thank you!

Answer 1

Welcome to Japanese stack exchange!

Your understanding of the sentence is correct, though you should be sure to translate the が, as "but", which I think adds the contrast needed to make your sentence sound less "wonky"!

The answer provided by the book is fine, too. か can be used between two nouns can mean "or", in an exclusive sense. As such, 「朝か晩に」 would mean "morning or evening", but not both. This would align with your translation of the more complex sentence.

You can use か just between the two nouns, as it is here i.e. 「N1 か N2」. But, you might sometimes see it used after both nouns i.e. 「N1 か N2 か」too, to mean the same thing (perhaps with more emphasis on the separate alternatives than the single か usage).