(for something) to turn on (Verb-う)
Stem	つき
	Positive	Negative
て	ついて	つかなくて
Plain	つく	つかない
Plain Past	ついた	つかなかった
Polite	つきます	つきません
Polite Past	つきました	つきませんでした
Plain Volitional	つこう	(To do...)
Polite　Volitional	つきましょう	(To do...)
Potential て	つけて	つけなくて
Plain Potential	つける	つけない
Plain Potential Past	つけた	つけなかった
Polite Potential	つけます	つけません
Polite Potential Past	つけました	つけませんでした
To write (Verb-う)
Stem	かき
	Positive	Negative
て	かいて	かかなくて
Plain	かく	かかない
Plain Past	かいた	かかなかった
Polite	かきます	かきません
Polite Past	かきました	かきませんでした
Plain Volitional	かこう	(To do...)
Polite　Volitional	かきましょう	(To do...)
Potential て	かけて	かけなくて
Plain Potential	かける	かけない
Plain Potential Past	かけた	かけなかった
Polite Potential	かけます	かけません
Polite Potential Past	かけました	かけませんでした
(for water, bath) to be boiled (Verb-う)
Stem	わき
	Positive	Negative
て	わいて	わかなくて
Plain	わく	わかない
Plain Past	わいた	わかなかった
Polite	わきます	わきません
Polite Past	わきました	わきませんでした
Plain Volitional	わこう	(To do...)
Polite　Volitional	わきましょう	(To do...)
Potential て	わけて	わけなくて
Plain Potential	わける	わけない
Plain Potential Past	わけた	わけなかった
Polite Potential	わけます	わけません
Polite Potential Past	わけました	わけませんでした
(for something) to be decided (Verb-う)
Stem	きまり
	Positive	Negative
て	きまって	きまらなくて
Plain	きまる	きまらない
Plain Past	きまった	きまらなかった
Polite	きまります	きまりません
Polite Past	きまりました	きまりませんでした
Plain Volitional	きまろう	(To do...)
Polite　Volitional	きまりましょう	(To do...)
Potential て	きまれて	きまれなくて
Plain Potential	きまれる	きまれない
Plain Potential Past	きまれた	きまれなかった
Polite Potential	きまれます	きまれません
Polite Potential Past	きまれました	きまれませんでした
To continue (something) (Verb-る)
Stem	つづけ
	Positive	Negative
て	つづけて	つづけなくて
Plain	つづける	つづけない
Plain Past	つづけた	つづけなかった
Polite	つづけます	つづけません
Polite Past	つづけました	つづけませんでした
Plain Volitional	つづけよう	(To do...)
Polite　Volitional	つづけましょう	(To do...)
Potential て	つづけられて	つづけられなくて
Plain Potential	つづけられる	つづけられない
Plain Potential Past	つづけられた	つづけられなかった
Polite Potential	つづけられます	つづけられません
Polite Potential Past	つづけられました	つづけられませんでした

Stem form usage

Purpose of going

This form serves as a purpose when the verb form is followed directly by the particle に and the sentence is ended with a movement verb such as "いきます", "きます", or "かえります".

I went to Japan to eat sushi. : すし　を　たべ　に　にほん　に　いきました。

I return home to play video games. : ゲーム　を　し　に　うち　に　かえります。

Expressing (personal) desire

Stem form can have "たい" appended in order to express a want; the ending is then used as an い-adjective and can be conjugated as such.

I want to eat sushi. :　すし　を　てべ　たい　です。

I don't want to eat sushi. : すし　を　たべ　たくない　です。

This form can be used in questions but it's used should be limited. It can be used to get further information about what someone want's to do but should not be used to ask someone, especially a superior, if they want to do something; it is seen as insulting. (See Polite Invitation form for a better alternative).

Expressing (someone else's) desire

The above can be used to express someone else's want if "そう" follows it. This use is essentially hearsay, "I heard that Smith wants to ..."

I heard that Smith wants to watch a movie. : スミスさん　は　えいが　を　みたい　そう　です。

て form usage

As a Connector

Used to string together multiple verbs. Only the last verb, whether it be the ending of the sentence or just a clause, is conjugated normally.

Smith and read. : スミスさん　は　たべて　よみました。

The person who is eating and reading is Smith. : たべて　よむ　ひと　が　スミスさん　です。

Requests

Used alone or joined with "くれませんか", "ください", or "くださいませんか", a request can be made with varying levels of politeness.

Watch. : みて

Please watch. : みて　ください

Can you watch? : みて　くれませんか

Could you please watch? : みて　くださいませんか

As a State of Being

When connected to "いる", the verb in question is being done right now or is an ongoing effect. This combination can then be treated as any other verb, conjugating the "いる" ending to fit the situation at hand.

The cat is fat. : ねこ　が　ふとって　います。

The "い" of "いる" may be dropped in more casual speech.

I am watching tv. : テレビ　を　みて　る。

Habitual Actions

If an action is done on a frequent basis, the above form can be used as long as a reptitious time is given.

I play games every day. : まいにち　ゲーム　を　しています。

Every week I buy clothes. : まいしゅう　ふく　を　かって　います。

As an Action Done in Advance, in Preparation

When connected to "おく", the verb in question has or will be done in advance for some purpose. Again, the "おく" part can be conjugated like any other verb.

(Speaking of) the test, I studied in advance. : テスト　は　べんきょう　して　おきました。

In more casual speech, the preceeding "て" or "で" may be combined with the following "お" as "と" or "ど".

Kim chilled the drinks in advance. : きむさん　は　のみもの　を　ひやしといた。

Expressing Completion, Possibly Regret and Realization

When combined with "しまう", the act of completion is more clearly defined. Additionally, dependent on context, it can express regret over an action which should have not happened. Once again this can be conjugated normally.

I am done eating. : たべて　しまいました。

Casual speech allows for a shortening of the form. "てしまう" to "ちゃう", "でしまう" to "じゃう"

I forgot my homework! : しゅくだい　を　わすれちゃった

Resulting State from an Intentional Action

"ある" may be used for states resulting from intentional actions. Again, the latter part can be conjugated normally.

Games have been bought in advance. : ゲーム　を　かって　ありました。

Direct objects in these instances may use either "を" or "が" as particles, with "を" being preferred for actions of the speaker.

Plain form usage

This form is also referred to as dictionary form.

Standard sentences to a social equal, inferior

Ending a sentence with a plain form is acceptable around friends and associates but should be avoided around bosses, teachers, and the like.

I will marry Alice : アリスさん　は　けっこん　　する。

I eat pizza. : ピザ　を　たべる。

Using verbs as nouns

In certain situations verbs may be used as a topic or otherwise be referred to as an object. One way this can be accomplished is by using the plain form of a verb and appending "の" to the end.

I like playing games. : ゲーム　を　する　の　が　すき　です。

Swimming is fun. : およぐ　の　は　おもしろい　です。

Using verbs to describe nouns

If a plain form verb directly preceeds a noun, the preceeding sentence clause can describe the noun.

The man taking the photograph is my dad. : しゃしん　を　とる　おとこ　の　ひと　が　ちち　です。

Giving reasons

This is a special case of the above when の　is followed by で and another full sentence. This particlar form of explanation is considered rather polite.

Because I study, I am busy. : べんきょう　する　の　で、　いしょがしい　です。

Giving reason

The particle "から" can be used to give reasons, connecting two sentences without the need for conjugation to plain form, although it can still be used.

Because I have a test, I study. : テスト　が　ある　から　べんきょう　します。

Because I play games, I don't sleep. : ゲーム　を　する　から　ねますえん。

Confirmation of an assumption, giving / requesting explanation, or expressing surprise / irritation

The meaning conveyed here is dependent on context. A setence ended with a plain form verb and "んです" forms a more forceful polite sentence while a plain form verb and "の" does the same for a standard sentence.

I eat sushi. : すし　を　たべる　んです。

I eat sushi. : すし　を　たべる　の。

Of course, this can also be used in questions. In polite speech the particle "か" must be appended to the end of the sentence, in a standard sentence you should raise your pitch at the end, same as in english.

Do you eat sushi? : すし　を　たべる　んです　か。

Do you eat sushi? : すし　を　たべる　の。　["の" being in a higher pitch.]

Using verbs to describe a point in time

If "とき" is the noun referenced, the clause refers to an incomplete or unstarted action. The full sentence does not have to end in the same tense.

When I play video games [literally: the time when I play video games] I don't sleep. : ゲーム　を　する　とき　に　ねません。

I didn't sleep when I played video games. : ゲーム　を　した　とき　に　ねませんでした。

Doing something although, but something else

The particles "けど" and "が" can be used to say that an action is performed despite something else. "が" is a softer form.

Although I have a test, I play games. : テスト　がある　けど　ゲーム　します。

I play games, but I have a test. : テスト　がある　が　ゲーム　します。

Expressing opinions

A plain form verb sentence ended with "と　おもいます" expresses a though or opinion.

I think Yamada will go to Japan. : やまださん　は　にほん　に　いく　と　おもいます。"

I don't think Yamada will go to Japan. : やまださん　は　にほん　に　いかない　と　おもいます。"

Uncertainty

A sentence can be marked as uncertain by ending with a plain form followed by "でしょう", "かもしれない", or "かな".

It will probably rain tomorrow. : あした　あめ　が　ふる　でしょう。

It might rain tomorrow. : あした　あめ　が　ふる　かもしれない。

It might rain tomorrow. : あした　あめ　が　ふる　かもしれません。

I wonder if it will rain tomorrow. : あした　あめ　が　ふる　かな。

Plain Past form usage

This form serves as a standard sentence ending for actions that have been performed in the past.

I drank beer. : ベール　を　のんだ。

I went to Japan last year. : きょねん　にほん　に　いった。

Giving reason

The particle "から" can be used to give reasons, connecting two sentences without the need for conjugation to plain form, although it can still be used.

Because I have a test, I study. : テスト　が　あった　から　べんきょう　しました。

Because I play games, I don't sleep. : ゲーム　を　した　から　ねました。

Doing something although, but something else

The particles "けど" and "が" can be used to say that an action is performed despite something else. "が" is a softer form.

Although I had a test, I played games. : テスト　があった　けど　ゲーム　しました。

I played games, but I had a test. : テスト　が　あった　が　ゲーム　しました。

Polite form usage

Standard sentences to social superiors, elders

This form serves as a standard polite sentence ending for actions being performed in the present or future, dependent on context.

I will marry Alice : アリスさん　は　けっこん　します。

I eat pizza. : ピザ　を　たべます。

Invitations

When a sentence is ended with a negative polite verb and the particle か, it is similar to the English phrase "Why don't you..."

Why don't you have some [literally: eat the] cake? : ケーキ　を　たべません　か。

Why don't we go to a movie? :　えいが　に　いきません　か。

Giving reason

The particle "から" can be used to give reasons, connecting two sentences without the need for conjugation to plain form.

Because I have a test, I study. : テスト　が　あります　から　べんきょう　します。

Because I play games, I don't sleep. : ゲーム　を　します　から　ねますえん。

Doing something although, but something else

The particles "けど" and "が" can be used to say that an action is performed despite something else. "が" is a softer form.

Although I have a test, I play games. : テスト　が　あります　けど　ゲーム　します。

I play games, but I have a test. : テスト　が　あります　が　ゲーム　します。

Polite Past form usage

This form serves as a standard polite sentence ending for actions that have been performed in the past.

I drank beer. : ベール　を　のみます。

I went to Japan last year. : きょねん　にほん　に　いきました。

Giving reason

The particle "から" can be used to give reasons, connecting two sentences without the need for conjugation to plain form.

Because I had a test, I studied. : テスト　が　ありました　から　べんきょう　しました。

Because I play games, I don't sleep. : ゲーム　を　しました　から　ねますえんでした。

Doing something although, but something else

The particles "けど" and "が" can be used to say that an action is performed despite something else. "が" is a softer form.

Although I had a test, I played games. : テスト　が　ありました　けど　ゲーム　しました。

I played games, but I had a test. : テスト　が　ありました　が　ゲーム　しました。

Polite Volitional form usage

Eliciting and making proposals

The volitional form is similar to the English "lets" or "shall".

Shall we eat　here? : ここ　に　たべよう　か。

Shall we go? : いこう　か。

Let's eat here. : ここ　に　たべよう。

Let's go. : いこう。

Polite Volitional form usage

Eliciting and making proposals

The volitional, "ましょう", form is similar to the English "lets" or "shall".

Shall we eat　here? : ここ　に　たべましょう　か。

Shall we go? : いきましょう　か。

Let's eat here. : ここ　に　たべましょう。

Let's go. : いきましょう。

Random 5

Stem form usage

Purpose of going

Expressing (personal) desire

Expressing (someone else's) desire

て form usage

As a Connector

Requests

As a State of Being

Habitual Actions

As an Action Done in Advance, in Preparation

Expressing Completion, Possibly Regret and Realization

Resulting State from an Intentional Action

Plain form usage

Standard sentences to a social equal, inferior

Using verbs as nouns

Using verbs to describe nouns

Giving reasons

Giving reason

Confirmation of an assumption, giving / requesting explanation, or expressing surprise / irritation

Using verbs to describe a point in time

Doing something although, but something else

Expressing opinions

Uncertainty

Plain Past form usage

This form serves as a standard sentence ending for actions that have been performed in the past.

Giving reason

Doing something although, but something else

Polite form usage

Standard sentences to social superiors, elders

Invitations

Giving reason

Doing something although, but something else

Polite Past form usage

This form serves as a standard polite sentence ending for actions that have been performed in the past.

Giving reason

Doing something although, but something else

Polite Volitional form usage

Eliciting and making proposals

Polite Volitional form usage

Eliciting and making proposals