Verbs in the 連用形 can be very noun-like. There is a hierarchy of how noun-like, but we’ll consider any degree of change in this way to be 連用形の名詞化. Whether the result is actually a true-noun, a limited noun, or rarely like a noun shouldn't distract us from noting how verbs in this form can clearly deviate from a truly verbal meaning.
First, let’s assume that a lot of verbs can at least be noun-like in some contexts. We can see at least five different types of resultant noun phrases.
Our example verb for this category is 光 (light). Although its meaning of radiance in 目の光 gets closer to its verb roots, if we were to say 〇が光り〇, we would treat 光り as a verb phrase in the 連用形. This difference between hikari and hikar-i. suggests that the first comes from the second, but it has lost its literal connection to the verb 光る. The second clearly has not and is merely a form of the second. In spelling, we distinguish the two for this verb, but that won’t always be a guarantee.
If the verb in which the noun comes from has disappeared, then it becomes even clearer how independent the noun is from its verbal root. Some examples including the following.
霧 (mist): Comes from the 連用形 of the old verb 霧る meaning “to mist”
相撲 (sumo wrestling): Comes from the 連用形 of the old verb 争（すま）ふ meaning to fight.
歌舞伎 (Kabuki theatre): Comes from the 連用形 of the old verb かぶく meaning “to tilt (one’s head)”.
Another interesting example is the verb 歌う. We find that there are two nouns derived from it: 歌 and 謡い. The 漢字 have the same reading here, but the words うた and うたい have different meanings. The first can mean song or even poem (though when meant to mean poem it is often spelled as 詩). You may even see the character 唄 to refer to a song akin to a lullaby. The latter, 謡い, refers specifically to Noh song. We see that the latter clearly comes from the 連用形. At first glance, it seems that 歌 is from the root of the verb. In reality, it is probably from the contraction of うたい.
This is a less drastic form of Type 1. For 連用形 of this type, it can be used like any other noun grammatically. It needs no context to be understood in isolation as a noun phrase with a specific meaning. This does not mean that the 連用形 can be used verbally. So, we could say that 光 may belong here.
Many verbs regarding psychological and emotional state are represented here as well as human cognitive activities, speech acts, and actions regarding expression.
1. ほとんどの臓器が日ごろ休みなく働き続けています。 （休む）
Almost all of your organs continue to work nonstop on a normal basis.
2. 疲れを感じたときは、自分の体が「休んで！」と言っているサインです。 （疲れる）
When you've felt fatigue, that's a sign from your body telling you "to take a rest!".
3. 薬と死の匂いがする場所から逃れる。 （匂う）
To escape from a place with the smell of medicine and death.
4. ISISの狙いはシリアとイラクの国境地帯にイスラム国家を樹立するところにあります。 （狙う）
The aim of ISIS is to establish an Islamic State in the border region between Syria and Iraq.
5. エジプト市民の望みは叶うのか。 （望む）
Will the hopes of the Egyptian people be fulfilled?
6. 新しい知らせを伝える。 （知らせる）
To inform on a new notice.
7. 魔女は森永家全員に呪いをかけた。 （呪う）
The witch put a curse on all of the Morinaga family.
8. 川の流れに沿って泳ぐ。 （流れる）
To swim along the current of the river.
9. 難読漢字の読みを覚える方法を教えてくれませんか。 （読む）
Could you teach me methods to remember the readings of difficult to read Kanji?
10. どうしても何時間も怒りが収まらない。 （怒る）
(My/X's) anger won't simmer down for hours no matter what.
Even though these are clearly nouns, they still individually can have odd restrictions.
11c. きょうの働きは疲れだったなあ。 X （働く & 疲れる）
In this example, we see a major restriction on 働き and 疲れ. Even when you replace them with the correct words, the grammar is still off. This demonstrates how semantic and syntactic restrictions work in unison to form natural utterances like 11a. Take into consideration Ex. 12, which demonstrates the most natural and common use of 行き as a suffix.
12. 日本行の飛行機に乗る。 （行く ＝ ゆく）
To ride a plain bound for Japan.
Many verbs need context to be used independently. The point here is at least they can be stand-alone nouns. They just need help to make any sense. Consider Ex. 13-14.
13a. 泳ぎは体にいいですね。X （泳ぐ）
Swimming is good for you.
14. やっぱり魚は泳ぎが速いね。 （泳ぐ）
Fish are definitely fast at swimming.
Ex. 13 demonstrates how if you give the wrong sort of help, you get a bad sentence. Many examples of this are found in set idiomatic phrases. Some require a XはYが structure to appear whereas others simply want a subject attribute. The requirements to have these sort of nouns work varies a lot, which is why the mastery of this type is going to very difficult. You have to in a sense get used to how Japanese phrases things, which is not an easy task.
15a. 高まりを感じる。X （高まる）
To feel an emotional high.
16. 彼は分かりが遅い。 （分かる）
He's a slow learner.
17. 画面の映りが悪いですね。 （映る）
The quality of the screen is bad, isn't it?
18. エンジンのかかりが遅い。 （かかる）
The engine starts up slowly.
19. 庖丁がなまって切れが悪くなった。 （切れる）
The kitchen knife has gotten dull and doesn't cut well.
20. 神経の伝わりを遮断することで痛みを和らげる治療です。 （伝わる）
This is a treatment to alleviate pain by circumventing neural transmissions.
21. 内臓は腐りが早い。 （腐る）
Innards rot quickly.
21. エアコンの効きが悪い。 （効く）
The air conditioning doesn't work well.
22. 今年はピーマンの出来がイマイチですよ。 （出来る）
The pepper turnout this year is not that good.
23. 喫煙などは、血の巡りを悪くする主な原因である。 （巡る）
Smoking and the like is a major factor in worsening blood circulation.
24. 細長く粘りのない米に馴染む。 （粘る）
To get to non-sticky thin rice.
25. 枝が湿っていて、焚き火の燃えが悪い。 （燃える）
The branches are damp, and so the bonfire's flame is bad.
The next group requires compounding. Do not think, though, that words can’t be in more than one category. Rather, we must truly investigate individual meanings of a word to determine what type it belongs to. For example, 出汁 (soup stock) comes from 出す and would be an example of Type 1. Aside from this, 出し needs to be in a compound like ゴミ出し to work as a noun.
Because of this required compounding, you do sometimes get sequential voicing.
26. プロでも雪下ろしは困難です。 （下ろす）
Removing snow is even difficult for professionals.
27. 江戸時代の根付を相続する。 （付ける）
To inherit netsuke from the Edo Period.
Item Note: Netsuke are small miniature carvings that are placed at the edge of cords hanging from a pouch of some sort.
28. 木造2階建てが全焼しました。 （建てる）
The wooden, two-story structure completely burned up.
29. 2014年の梅雨入りは6月8日と言われています。 （入る ＝ いる）
They say that the start of 2014's rainy season was June, 8th.
30. 数字合わせ錠を使うのが便利です。 （合わせる）
Using a number combination lock is convenient.
31. 昼寝のあとに頭痛がします。 （寝る）
I have headaches after an afternoon nap.
32. 失策の穴埋めを国民に求める。 （埋める）
To seek the patching of a failed policy from the people.
33. 鮭と野菜をごちゃ混ぜにして焼きます。 （混ぜる）
We mix salmon and vegetables together and cook them.
34. 結婚の話が立ち消えになった。 （消える）
The talk of marriage fizzled away.
35. 人々の行き来が賑やかだった。 （来る）
The coming and going of people was lively.
連用形 → Noun → する Verb
At times, a noun made in this way may attach to another noun, but to be used verbally again, it needs to become a verb by adding する, which will be introduced shortly. As we haven't gone over how to conjugate this verb yet, we'll just look at some examples of this phenomenon. Consider the following words.
|目隠しする||めかくしする||To blindfold||タグ付けする||たぐつけする||To tag|
|粗探しする||あらさがしする||To nitpick||拾い読みする||ひろいよみする||To browse|
Part of Speech Note: The あら in 粗探し is actually from the stem of the adjective 粗い (rough/coarse).
In the grammar pattern 連用形＋に＋Motion Verb plus a few other instances we’ll see later on in Japanese grammar, verbs that do or don’t fall in the categories above are able to be used like nouns while simultaneously holding onto their verbal meaning.
If you want to say things like “I am going to watch the movie”, you must use this grammar pattern. The Japanese for this is 私は映画を見に行きます. The grammar is very parallel to English. In both languages, we would never call the verb a noun, per say. However, it certainly behaves like one in this situation.
If the verb is a する verb made by putting する after a Sino-Japanese word, then you don’t even need し. So, say you want to say, I’m going to observe at Kyoto University. You could say 京都大学を見学しに行きます. However, you could just say 京都大学を見学に行きます. Either way is grammatically fine.
I walked to search for strawberries by myself.
I rushed to return to get my luggage.
He came to play.
To come to discuss.
To go shopping.
Sentence Note: 買い物をする is the verb phrase!
Phrase Note: ～物 attaches to the 連用形 of verbs of type 4 to refer to the things that you do the action with. So, 飲み物 = drink, 食べ物 = food, and 読み物 = reading (material).
We came to see a movie.
Will you come to eat dinner?
My wife went home to go get her handbag.