Particles #1: Use の and こと to Use a Verb as the Topic of a Japanese Sentence
Updated: Apr 13, 2021
Adding の or こと to the end of a verb nominalizes it—in other words, it turns the verb into a noun. By doing this, you can put a verb in the topic position.
You can add の/こと only to the plain form of a verb, not the polite form.
In general, Japanese speakers tend to use の for this purpose when talking about something subjective and こと when discussing something objective.
Sentence Structure #1
[Verb] の (or こと) は [adjective or noun] です。
[Verb] no (or koto) wa [adjective or noun] desu.
[Verb]ing is [adjective or noun].
In both English and Japanese, you need to change verbs into nouns when using them in certain parts of a sentence (linguists refer to this as nominalization).
In English, you can use a verb as the subject of a sentence after nominalizing it by adding the suffix -ing. In Japanese, you need to nominalize a verb by adding a particle after it (either の or こと) if you want to put it in the topic position of a sentence.
の is usually used when talking about something subjective (e.g., your likes/dislikes). こと is used when discussing something factual.
Note that these particles can be added only to the plain/dictionary forms of verbs. You will sound strange to a native Japanese speaker if you use these after the polite (masu) form of a verb.
Utau no wa muzukashii desu.
Singing is difficult.
Neru koto wa spo–tsu ja nai.
Sleeping is not a sport.
Sentence Structure #2
[Object] を [verb] の (or こと) は [adjective or noun] です。
[Object] o [verb] no (or koto) wa [adjective or noun] desu.
[Doing something] is [adjective or noun].
Sentence Structure #1 can be expanded by using an entire object+verb phrase as the topic of a sentence. Simply precede the verb with the appropriate object and object-marking particle.
Nihongo o benkyousuru no wa sugoku omoshioroi desu.
Studying Japanese is very interesting.
Kyuuka-go, watashi no beddo ni neru koto wa ii.
It's nice to sleep in my bed after a vacation.