The Compound Verb 着替える (kigaeru) and a Question of Particles

Japanese is rife with compound verbs, which are generally composed by taking the verb stem (what I like to call the ‘pre-masu form’) of one verb and attaching it to a second verb. For example 食べ終わる (“tabeowaru”) which is comprised of the verb stem of 食べる (“taberu”, meaning “to eat”) and 終わる (“owaru”, meaning “to end”).

In many cases the resultant meaning can be easily inferred from the meanings of the two words, as in 食べ終わる, which means “to finish eating”. Verbs like this are conjugated like any other verb (ex: 食べ終わってください).

In this article I wanted to focus on the verb 着替える (“kigaeru”), for which the particle usage is a little tricky (let’s just say I found this out the hard way…)

This verb is comprised of 着る (“kiru”) plus 替える (“kaeru”), verbs which respectively mean “to wear (clothes)” and “to exchange or replace”. As in the previous example, you can probably guess that the meaning is “to change clothes”. But which particle should you use? First, let’s look at the particle usage of each of these two verbs.

着る generally takes the particle を (“o” or “wo”), which specifies the object of an action. For example:

•  まだジャケットを着ていない (mada jaketto wo kite inai)
• (I’m) not wearing a jacket yet.

替える is a bit more complex since there are two things involved, the thing you are changing from and the thing you are changing to, though in some cases one (or even both) may be only implied. In Japanese, we use を for the “from” object and the に for the “to”. You might wonder why から is not used instead of を, and I think the best way to understand this is that the verb is taking the “from” object as the main object and then acting on it to change/replace it to something else. Let’s look at an example:

• 小銭を札に替えたいです (kozeni wo satsu ni kaetai desu)
• I’d like to change coins into paper money.

By the way, you can use the particle と (“to”) instead of に for the “from” object, though it sounds a bit more formal/stiff to me, and I would recommend using に in conversation.

Now what about 着替える? Let’s look at one option:

•  シャツが汚れたから新しいシャツを着替えたい（shatsu ga yogoreta kara atarashii shatsu wo kigaetai) [???]

At first glance this usage, where we are using を as we would for 着る, seems legitimate. But in fact this would mean:

• My shirt got dirty so I want to change out of a new shirt.

Here “out” expresses the fact we are dealing with the “from” object of the changing action. This sentence doesn’t make sense since we aren’t even wearing the new shirt, and yet we are trying to change out of it (meaning take it off and put something else on). 

It turns out that 着替える uses particles just like 替える does, so we should use the に particle to express what we are changing to. Let’s rewrite the above sentence to make a correct one:

•  シャツが汚れたから新しいシャツに着替えたい（shatsu ga yogoreta kara atarashii shatsu ni kigaetai)
• My shirt got dirty so I want to change into a new shirt.

Just as Japanese uses を and に to specify each object, English uses the prepositions “out of” and “in to” to clarify the roles. It should be pointed out that Japanese generally omits words and phrases whenever they can be inferred from context, so perhaps the below is a slightly more natural sentence:

•  シャツが汚れたから着替えたい（shatsu ga yogoreta kara kigaetai)