Definition: All auxiliary verbs in Japanese attach to a verbal or adjectival stem form and conjugate as verbs, the auxiliars verbs are different to normal verbs in having no independent meaning as a normal verb. In modern Japanese there are two distinct classes of auxiliary verbs.
| Auxiliar | Example | 
| ます (masu) | 書く (kaku, to write) → 書きます(kakimasu) | 
| られる(rareru) | 見る (miru, to see) → 見られる (mirareru, to be able to see) 増える (fueru, to increae) → 増えられる (fuerareru, to have the ability to increase) | 
| る (ru) | 飲む (nomu, to drink/swallow) → 飲める (nomeru, to be able to drink) | 
| させる (saseru) | 考える (kangaeru, to think) → 考えさせる (kangaesaseru, to cause to think) | 
| せる (seru) | 思い知る (omoishiru, to realize) → 思い知らせる (omoishiraseru, to cause to realize/to teach a lesson) | 
These are normal verbs that lose their independent meaning when used as auxiliaries.
| Auxiliar | Example | 
| ある (aru, to be (inanimate)) | 開く (aku, to open) → 開いてある (aite-aru, opened and is still open) | 
| いる (iru, to be(animate)) | 寝る (neru, to sleep) → 寝ている (nete-iru, is sleeping) | 
| いく (iku, to go) | 歩く (aruku, to walk) → 歩いていく (aruite-iku, keep walking) | 
| くる (kuru, to come) | なる (naru, become) → なってくる (natte-kuru, start becoming) | 
| 始める (hajimeru, to begin) | 書く (kaku, to write) → 書き始める (kaki-hajimeru, start to write) | 
| 出す (dasu, to emit) | 輝く (kagayaku, to shine) → 輝き出す (kagayaki-dasu, to start shining) | 
| みる (miru, to see) | する (suru, do) → してみたい (shite-mitai, try to do) | 
| なおす (naosu, to correct/heal) | 書く (kaku, to write) → 書きなおす (kaki-naosu, rewrite) | 
| あがる (agaru, to rise) | 立つ (tatsu, to stand) → 立ち上がる (tachi-agaru, stand up) 出来る (dekiru, to come out) → 出来上がる (deki-agaru, be completed)  | 
| 得る (eru/uru, to be able) | ある (aru, to be) → あり得る (arieru, is possible) | 
| かかる (kakaru, to hang/catch/obtain) | 溺れる (oboreru, drown) → 溺れかかる (obore-kakaru, about to drown) | 
| きる (kiru, to cut) | 食べる (taberu, to eat) → 食べきる (tabe-kiru, to eat it all) | 
| 消す (kesu, to erase) | 揉む (momu, to rub) → 揉み消す (momi-kesu, to rub out, to extinguish) | 
| 込む (komu, to enter deeply/plunge) | 話す (hanasu, to speak) → 話し込む (hanashi-komu, to be deep in conversation) | 
| 下げる (sageru, to lower) | 引く (hiku, to pull) → 引き下げる (hiki-sageru, to pull down) | 
| 過ぎる (sugiru, to exceed) | 言う (iu, to say) → 言いすぎる (ii-sugiru, to say too much, to overstate) | 
| 付ける (tsukeru, to attach) | 行く (iku, to go) → 行き付ける (iki-tsukeru, be used to (going)) | 
| 続ける (tsuzukeru, to continue) | 降る (furu, to fall (eg. rain)) → 降り続ける (furi-tsuzukeru, to keep falling) | 
| 通す (tōsu, to show/thread/lead) | 読む (yomu, to read) → 読み通す (yomi-tōsu, to finish reading) | 
| 抜ける (nukeru, to shed/spill/desert) | 走る (hashiru, to run) → 走り抜ける (hashiri-nukeru, to run through (swh)) | 
| 残す (nokosu, to leave behind) | 思う (omou, to think) → 思い残す (omoi-nokosu, to regret (lit: to have sth left to think about)) | 
| 残る (nokoru, to be left behind) | 生きる (ikiru, live) → 生き残る (iki-nokoru, to survive (lit: to be left alive)) | 
| 分ける (wakeru, to divide/split/classify) | 使う (tsukau, use) → 使い分ける (tsukai-wakeru, to indicate the proper way to use) | 
| 忘れる (wasureru, to forget) | 聞く (kiku, to ask) → 聞き忘れる (kiki-wasureru, to forget to ask) |