Basic Conjugation (Polite Form)

When you conjugate verbs in English, you have to consider the tense (present, past, future, etc.) and the subject (I, you, he/she/it, we, they). When conjugating verbs in Japanese, although you must still consider the tense, the subject is unimportant; in other words, the same verb conjugation can be used regardless of the subject. For example, “wakarimasu” can mean “I understand,” “you understand,” “he/she/it understands,” “we understand,” and “they understand”!

However, there is something more you must consider when conjugating verbs in Japanese: the person/people to whom you are speaking. There are multiple levels of formality in the Japanese language. You wouldn’t use the same form of a verb when speaking to your best friend that you would when speaking to a business client or your boss—and you certainly wouldn’t speak to the emperor of Japan with the same level of formality that you would to your boss, even though that level of formality is usually quite polite!

However, there are only two levels of formality with which you need to concern yourself to achieve a passable level of fluency in Japanese: informal (the shortest form of verbs) and basic formal (the shortest formal form of verbs). These are often called the plain and polite forms of Japanese verbs. As it’s always better to err on the side of being overly formal when speaking Japanese, we’re going to start by studying the polite present and polite past tense of the three verb groups.

Conjugating Group 1 Verbs (Godan-doushi, Verbs Ending in “U”)

Polite Present Tense: The ~masu Form

If you studied the Special Notes Section of the first Verb Groups lesson, you might remember that one of the “five steps” of the godan-doushi (“five step verbs”) is the i infinitive form stem. This is what you will use to conjugate Group 1 Verbs into the polite present tense.

If that sounds confusing, don’t worry. All you need to remember is this:

  1. Identify the verb as a Group 1 Verb, a verb ending in “u.” (The verb either does not end in “ru” or is a verb that ends in “ru” that you have memorized to be a Group 1 Verb and the verb is not an irregular verb.) Let’s take the verb aruku (“to walk”) as our example.
  2. Remove the “u” at the end of the verb. This is the verb stem. Now we have aruk-.
  3. Add “~imasu” at the end of the verb. Now we have arukimasu. This is the conjugated verb.


Polite Past Tense: The ~mashita Form

The polite past tense conjugation of a Group 1 Verb is very similar to the polite present tense conjugation, but instead of adding “~imasu,” we add “~imashita.” Let’s try it:


  1. Identify the verb as a Group 1 Verb, a verb ending in “u.” Let’s take the verb aruku (“to walk”) again as our example.
  2. Remove the “u” at the end of the verb. This is the verb stem. Now we have aruk-.
  3. Add “~imashita” at the end of the verb. Now we have arukimashita. This is the conjugated verb.


Try to conjugate all of the Group 1 Verbs we’ve studied so far in the polite present and polite past tense:

<td “=””> Stem <td “=””> Polite Present Tense

Group I Verb Polite Past Tense
aruku – “to walk” aruk- arukimasu arukimashita
au – “to meet” a- aimasu aimashita
hanasu – “to speak” hanas-* hanashimasu* hanashimashita*
iku – “to go” ik- ikimasu ikimashita
kaku – “to write” kak- kakimasu kakimashita
matsu – “to wait” mats-* machimasu* machimashita*
nomu – “to drink” nom- nomimasu nomimashita
yobu – “to call” yob- yobimasu yobimashita
hairu – “to enter” hair- hairimasu hairimashita
hashiru – “to run” hashir- hashirimasu hashirimashita
iru – “to need” ir- irimasu irimashita
kaeru – “to return” kaer- karimasu kaerimashita
kiru – “to cut” kir- kirimasu kirimashita
mairu – “to come” mair- mairimasu mairimashita
shaberu – “to chat” shaber- shaberimasu shaberimashita
shiru – “to know” shir- shirimasu shirimashita
tsukuru – “to make” tsukur- tsukurimasu tsukurimashita


*Notice that that hanasu and matsu do not become hanasimasu and matsimasu respectively. This is because there are no “si” and “tsi” forms in natural Japanese. Therefore, they must be replaced by the closest equivalents in Japanese, which are “shi” and “chi.”