The difference between 何の and どんな

When learning a foreign language, once you learn the basics you should always strive to be humble and never assume you have a perfect understanding. This reminds me of the expression “油断大敵” (yudan taiteki) which translates to something like “careless is your worst enemy”. In other words, letting your guard down for just a moment can be your end, regardless of how skillful you are.

This post is a brief episode about how I let down my guard regarding some basic Japanese grammar.

It concerns the expressions “何の〜” (What ~) and “どんな〜” (What kind of ~). I was pretty sure I understood these, and when I was reading a Shimajiro book to my son, there was a part where the sounds of various cars was introduced. For example “ブロロロ” is the sound of a bus. These are interesting in themselves since they are quite different from equivalent English words, but what I’d like to focus on is what I said to my son next.

“パトカーは何の音？”

in this case ”パトカー” is a loanword from English which means “Patrol car”, basically “police car”, and I was trying to ask “What type of sound is made by the police car?”

I had used “何の音” since I felt it meant “what sound?” and assumed this fit the context.

However, as this was completely wrong I was promptly corrected by my wife.

She told me ”何の音” in practical use essentially meant “誰の音” (whose sound) and describes who is making a certain sound.

So it would be correct to say “「ブロロロ」は何の音?“, and the answer would be “a bus”.

However, “パトカーは何の音?” is incorrect because it translates to something like “The police car has whose sound?”.

Accordingly, the proper phrase here would be “パトハーはどんな音？”, which means “The police car has what type of sound? “. If you’re curious, the answer is “ピーポーピーポー”.

Here is another example of these two phrases with their English translations:

• それは何の本？  => What book is that? (i.e. what is the name)
• それはどんな本？  => What type of book is that? (i.e. looking for a category)