Making a question sentence in Japanese is easy, just add -か (ka) at the end of the sentence! –か (ka) changes the connotation of
the sentence. For example:
にほんじんです (nihonjin desu) (I) am Japanese.
にほんじんですか (nihonjin desu ka) (Are you) Japanese?
Once we add the -か (ka) to the sentence, what was a statement becomes a question. In English, the pitch of our voice changes slightly between a statement and a question. The same holds true with a Japanese question. When we say -か (ka) at the end of a question, we pitch our voices slightly higher. This change in pitch comes incredibly important when we make informal questions.
Notice these are both yes/no questions. To make a question where the other person must give a full answer, we use specific question words.
Just like in English, there are specific question words in Japanese. Let's go over some of the Japanese question words, and use them in some sentences:
なん/なに (nan/nani) what
Both なん (nan) and なに (nani) mean "what" in Japanese. なん is a shortened version of なに, so many times it comes down to preference for use. Let's see both なん (nan) and なに (nani) in sentences:
せんもん は なん です か (senmon wa nan desu ka) What is your major?
なに を よみます か (nani wo yomimasu ka) What are you reading?
Notice that なん (nan) and なに (nani) replace the word that would be our response, thus not making it a yes/no question. When using a question word, its placement depends on where the response word would go in a statement sentence.
Another question word is なんじ (nanji), which means "what time is it?" (notice the なん in なんじ):
いま なんじ です か (ima nanji desu ka) What time is it now?
いま は いちじ です (ima wa ichiji desu) It's one o'clock.
Just like the なん (nan) and なに (nani) sentences, なんじ (nanji) appears in the question where our answer would be. なん (nan) can also be added to make other question words, such as:
なんさい (nansai) How old?
なんねんせい (nannensei) What year (as in school year)?
Remember when using a なん (nan) question word to place it in the question where the answer would logically go.
Now that we have a handle on making a question in Japanese, let's throw a wrench into the equation. When we are speaking informally, such as to a friend, we can eliminate the か at the end of the sentence. Also, the か is dropped when we are talking or writing in short-form Japanese. We will discuss more about short-form Japanese in another lesson.
Banno, E., Ohno, Y., Sakane, Y. and Shinagawa, C. An Integrated Course in Elementary Japanese. The Japan Times, 1999