An embedded question is when a sentence contains a question inside of it, for example “I don’t know where Japan is”. Sentences with embedded questions can be declarative statements like that example, or instead can be questions themselves, as in “Do you know where Japan is?”. An example of a non-embedded question would be the basic sentence “Where is Japan?”.
As a fluent English speaker, all of us already know the rules for making embedded questions in English, but you may not be consciously aware that when making an embedded question sometimes the word order changes. For example, in the above examples, “where is Japan” changes to “where Japan is” when embedded into a larger sentence.
One nice thing about Japanese language is that making embedded questions is simpler because you never have to worry about word order changing. In fact this also applies to non-embedded questions, since those have word order changes in English as well (ex: “It is cold” => “Is it cold?”).
The most important thing to know about embedded questions in Japanese is you always need to add the question particle “か” after the question. The か particle may be used in non-embedded questions, though this is much more common when speaking in polite language, and can add a rough feel to non-polite language (i.e. “やるか？” sounds like you are instigating a fight)
To me, this intuitively makes sense because without word order changes like English the listener would have a harder time understanding the sentence without a hint there is a question involved.
Let’s look at how we would say some of the above example sentences in Japanese, using polite language.
- Where is Japan?
- I don’t know where Japan is.
- Do you know where Japan is?
In the last two sentences (both embedded questions), the word ”だ” could be inserted before the ”か”, though that is used a little less in my experience and has a certain rough feeling to it.
In the above examples, the some detail about a topic is being asked so the question word (どこ) at end end of the embedded question, right before the か. However, if question is about who/what/which was the subject of an action or had a certain characteristic, you would use a question word followed by が at the beginning of the embedded question.
- I know who ate the cookie.
- I don’t know which is good.
The same pattern applies when there is no question word used. In English words like “if” or “whether” would be employed, but in Japanese none such are necessary.
- I don’t know if it’s cold.
You can, however, use the pattern “かどうか” if you want to emphasize you don’t know whether something is true or not. Alternatively, you can use “(positive statement) + か + (negative statement) +か”, though I feel this is extra verbose and less commonly used. For example:
- I don’t know if it’s cold or not.
You can use two or more embedded questions by placing them one after another, like in this example:
- I don’t know whether he is sleeping or awake.
In the above examples I have only used the verbs 知る (to know) and 分かる (to understand), but there are many other verbs that can be used after an embedded question, such as “考える” (to think), ”確認する” (to verify), and “迷う” (to be indecisive, can’t decide). In fact, verbs that don’t usually relate to doubt, consideration, knowledge, or understanding can be used. Here is one such example using 見る (to see).
- Today, we are just going to see if there are any cavities.
Here we can see an important pattern in Japanese embedded questions – when checking for something usually the negative form is used (虫歯がないか）, which contrasts with English where the positive form is used (if there are any cavities).
Similies, where one thing is compared to another using “like” or “as”, can be represented in Japanese using an embedded question followed by “のように”.
- She really enjoyed the chocolate, as if it had been her first time eating it.
The “のように” can be omitted altogether for the same meaning, though I have mostly seen this usage in literature.