Verb Basics

Role of Verbs

We've now learned how to describe nouns in various ways with other nouns and adjectives. This gives us quite a bit of expressive power. However, we still cannot express actions. This is where verbs come in. Verbs, in Japanese, always come at the end of clauses. Since we have not yet learned how to create more than one clause, for now it means that any sentence with a verb must end with the verb. We will now learn the two main categories of verbs, which will allow us to accurately define rules for conjugation. Before learning about verbs, there is one important thing to keep in mind.

Or to rephrase, unlike English, the only thing you need to make a grammatically complete sentence is a verb and nothing else! Understanding this fundamental property is essential to understanding Japanese. That's why even the simplest, most basic Japanese sentence cannot be translated into English! All conjugations will start from the dictionary form (as they appear in the dictionary).

A grammatically complete sentence
（１）　食べる。- Eat. (possible translations include: I eat/she eats/they eat)

Classifying verbs into ru-verbs and u-verbs

Almost all verbs in Japanese can be classified into two categories: ru-verb （一段動詞） and u-verbs （五段動詞）. The only two verbs that are not considered to be in either category are 「する」 meaning "to do" and 「来る」 meaning "to come". Otherwise, the rules for conjugation are almost all the same depending on what class the verb is in. The way to distinguish between these verbs is fairly straightforward.

Remember, every verb has a string of kana called okurigana, which you can modify to conjugate the verb. If you convert the verb to Roman characters (called 「ローマ字」 in Japanese) and it ends in either "iru" or "eru", then it is usually a ru-verb. For example, 「食べる」 is romanized as "taberu" and since it ends in "eru", it is a ru-verb. Another example of a ru-verb is 「起きる」, which romanizes to "okiru". All other verbs that do not end in "iru" or "eru" are u-verbs.

However, there is just one snag here. Notice that all ru-verbs end with 「る」 and u-verbs always end in a / u / vowel sound. This unfortunately includes 「る」 in addition to 「つ」、「す」、「く」、「ぐ」、「む」、「ぶ」、「う」、and 「ぬ」 （「死ぬ」 is the only verb that ends in 「ぬ」）. Even if a verb ends with 「る」, if it does not end in "iru" or "eru", it is always an u-verb. However, there are a number of u-verbs that end in "iru" or "eru" and there is no way to distinguish them from regular ru-verbs apart from memorization. You can refer to the appendix at the end of this lesson for a list of such verbs. You can also refer to Jim Breen's WWWJDIC, if you have any doubts. Ru-verb are denoted as (v1) while u-verbs are denoted as (v5).

Because of the aural consistency in the rules, with practice, u-verbs will start to "sound" like u-verbs and likewise for ru-verbs. Eventually, you'll be able to categorize new verbs just like that without giving it a second thought. Or at least, that should be the intended goal.

Examples

Here are some example sentences using ru-verbs, u-verbs, and exception verbs.
（１）　アリスは食べる。- As for Alice, eat.
（２）　ジムが遊ぶ。- Jim is the one that plays.
（３）　ボブもする。- Bob also do.
（４）　お金がある。- There is money. (lit: As for money, it exists.)
（５）　私は買う。- As for me, buy.
（６）　猫はいる。- There is cat. (lit: As for cat, it exists.)

Appendix: iru/eru u-verbs

Here is a list of commonly used u-verbs that end in "iru" or "eru". This list is categorized roughly into three levels to help you focus on the verbs you need to learn. This list is not intended to include every verb under the sun.