What You Need to Know About Japanese Verb Stems
Knowing how to take a Japanese verb and turn it into stem form is very useful. Even if you only began studying Japanese recently, it is, in fact, likely that you already know at least one or two sentence patterns that use verb stems. In this article, we will show you how to turn any verb into its stem form, and then give seven verb-stem sentence patterns.
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First, let’s take a look at how to get a verb stem
As with most verb conjugation patterns in Japanese, getting the stem form of a verb is a different process depending on if it is a Ru Verb or an U Verb.*
1. If your verb is a Ru Verb, just remove the final “ru” to get the verb stem.
食べる → 食べ (Taberu → Tabe)
Every dictionary form Japanese verb ends with a syllable that is a consonant plus the vowel “u.” When changing an U Verb to stem form, that vowel changes to an “i,” which (because Japanese is written in syllables) means that the final hiragana of the verb must change. To double check which kana you are changing to, slide down the row of your hiragana chart, keeping the consonant the same:
飲む → 飲み (Nomu → Nomi)
2. Occasionally, sliding down a consonant row (for example, the “T” row) of your chart will result in a different consonant.
待つ → 待ち (Matsu → Machi)
3. Japanese’s two common irregular verbs, Suru and Kuru, have the stem forms Shi and Ki.
する → し (Suru → Shi)
来る → 来 (Kuru → Ki)
*Japanese essentially has two types of verbs: Ru Verbs and U Verbs. If a verb does NOT end with る ru, it is an U Verb. However, some verbs that end with る ru are Ru Verbs, and some are U Verbs! Sadly there is no surefire way to know whether verbs like 乗る noru and 借りる kariru are U Verbs or Ru Verbs other than to look them up, but as you study you will eventually gain a feeling for which are which.
One way to check is to run a verb through a few conjugations. For example, the polite conjugation of 乗る noru is 乗ります norimasu because it is an U Verb. If we try conjugating it as 乗ます nomasu instead (as we would if it were a Ru Verb), it just does not sound quite right.
Uses for JAPANESE VERB STEMS
Note: In all of our examples, we are leaving out the topic “I” at the beginning of the sentences. When it is understood that the topic of the sentence is oneself, saying “I” is not needed. This also means that if spoken in a different situation, the topics of these sentences could be someone other than the speaker (“she,” “he,” “they,” etc).
1. Making -masu form/polite verbs
Usually, -masu form verbs are the first type of verb you are taught to use when beginning to learn Japanese. This is because -masu form verbs are quite easy to use and conjugate, and also because they are fairly polite.
How to make masu form verbs
1. To make a -masu form verb, simply attach “-masu” to the end of your verb stem.
A -masu form verb and the dictionary form verb it was built from are the same tense and mean essentially the same thing. The -masu form verb is just more polite. For example:
Inu o tasukeru.
I will help the dog.
Inu o tasukemasu.
I will help the dog.
2. To make different tenses in -masu form, all you need to do is remove the -masu and attach something different to that verb stem.
Inu o tasukemasen.
I will not help the dog.
Inu o tasukemashita.
I helped the dog.
Inu o tasukemasendeshita.
I did not help the dog.
2. Saying that you want to do an action
To say that you want to or do not want to do something, add たいです tai desu or たくないです taku nai desu (respectively) onto your verb stem:
Inu ga tasuke tai desu.
I want to help the dog.
Inu ga tasuke taku nai desu.
I do not want to help the dog.
Note that these patterns should be used when talking about what you want to or do not want to do, but not when talking about other people. When talking about what someone other than oneself wants or does not want to do, add ただって tagatte imasu or たがっていません tagatte imasen onto your verb stem:
Inu o tasuke tagatte imasu.
She/he wants to help the dog.
Inu o tasuke tagatte imasen.
She/he does not want to help the dog.
3. Saying that you will go to a place to do an action
To say that you will go/come to a place in order to do an action, or that you will go/come to a place in order to do an action there, add に行きます ni ikimasu or に来ます ni kimasu onto your verb stem:
Inu o tasuke ni ikimasu.
I will go (somewhere) to help the dog.
Inu o tasuke ni kimasu.
I will come to (somewhere) to help the dog.
4.Saying that you are doing one action while doing another action
To express doing two actions at the same time (for example, listening to music while studying, or reading your texts while brushing your teeth), add ながら nagara onto the stem form of verb 1, and then place verb 2 (not in stem form) after the ながら nagara:
Inu o tasuke nagara, tonari no hito to hanashimashita.
While I helped the dog, I spoke to my neighbor.
5. Creating humble and honorific verbs
Dictionary form verbs are fine for conversations with friends, and -masu form verbs are plenty polite for most other situations. However, in situations where you need or want to be extra polite, humble and honorific verbs can be used instead of -masu verbs. To create a humble or honorific verb, add お o to the front of your verb stem, and either します shimasu (humble) or になります ni narimasu (honorific) after the verb stem:
Inu o otasuke shimasu.
I will help the dog.
Inu o otasuke ni narimasu.
(Someone else) will help the dog.
For more on humble and honorific verbs, please see our Keigo article.
6. Saying “how to [action]”
To express the idea of “how to do [action]” (for instance, “the way to make bread” or “how to read kanji”), add 方 kata after your verb stem:
Inu no tasuke kata o oshiete kudasai.
Please tell me the way to help a dog.
One last note:
In spoken Japanese, you will frequently hear stem form verbs used in the patterns above, but you will not usually hear them used by themselves. However, in written Japanese (including in articles, books, and song lyrics), stem form verbs can be used to indicate “and”:
Inu o tasuke, ie ni kaerimashita.
I helped the dog, and went home.
This use of stem form is similar to one of the uses of –Te Form that we discussed in our What Exactly is -Te Form? article.
That’s all for now on stem form verbs! There are a few additional stem form patterns that we did not have time to discuss in this article, so if you have any questions, please do leave us a comment! Also, feel free to let us know if there are any grammar patterns, conjugations, or other topics you would like to request an article about. We want to know what you want to know!