Overview
This lecture covers every major Japanese verb conjugation, explaining how to identify verb types and apply conjugation rules for all standard forms, including exceptions.
Japanese Verb Types
- Japanese verbs are categorized as ichidan (ru-verbs) and godan (u-verbs).
- Ichidan verbs have one-stage conjugation: drop "ru" and add the ending.
- Godan verbs' conjugation depends on the verb's final syllable.
- To identify verb type: if the pre-ending vowel before "ru" is "i" or "e," it's likely ichidan; otherwise, godan, with some exceptions.
- The nai-form method is 100% accurate: if the nai-form has "e/nai" or "i/nai," it's ichidan; otherwise, godan.
- Irregular verbs: kuru (to come), suru (to do), and aru (to exist) have special rules.
Dictionary Form (Plain/Casual)
- The dictionary form is the base form, used in casual speech and references.
- Ichidan: simply use the verb.
- Godan: verb ends in "u" sound.
Polite Form (Masu Form)
- Ichidan: drop "ru," add "masu" (e.g., tabemasu).
- Godan: change final sound to the "i" row and add "masu" (e.g., kiku → kikimasu).
- Kuru → kimasu, suru → shimasu.
Verb Stem (Masu-stem)
- Ichidan: drop "ru" or "masu" leaving the stem.
- Godan: drop "masu" from polite form.
- Used for attaching other grammar (e.g., "-tai" for "want to").
Te-form
- Ichidan: drop "ru," add "te."
- Godan: ending changes depend on verb ending (see key).
- Used for connecting actions and requests (e.g., kudasai).
Past Tense (Ta-form)
- Replace "te" with "ta" or "de" with "da" in te-form.
- Ichidan: stem + "ta."
- Godan: follow te-form logic, replace ending.
Continuous/Progressive (Te-iru)
- Te-form + "iru" means an action is ongoing or a state exists.
- Te-iru may contract to "-teru" in casual speech.
Negative Form (Nai-form)
- Ichidan: stem + "nai."
- Godan: change final sound to "a" row + "nai."
- Polite negative: "-masen."
- Exceptions: aru → nai, kuru → konai, suru → shinai.
Past Negative (Nakata-form)
- Replace "nai" with "nakatta."
- Polite: "-masen deshita."
Passive Form
- Ichidan: stem + "rareru."
- Godan: change final sound to "a" row + "reru."
- Kuru: korareru; suru: sareru.
Causative Form
- Ichidan: stem + "saseru."
- Godan: change final sound to "a" row + "seru."
- Kuru: kosaseru; suru: saseru.
Causative-Passive Form
- Combine causative and passive: stem + "saserareru" (ichidan), godan: final sound to "a" row + "saserareru."
- Rare for su-ending godan verbs.
Imperative (Command) Form
- Ichidan: stem + "ro."
- Godan: change final sound to "e" row.
- Kuru: koi; suru: shiro.
Conditional Forms
- Ba-form: ichidan stem + "reba;" godan final sound to "e" row + "ba."
- TARA-form: past (ta-form) + "ra;" works for all verb types.
Potential Form
- Ichidan: stem + "rareru" (may contract to "reru" in casual speech).
- Godan: final sound to "e" row + "ru."
- Kuru: korareru; suru: dekiru.
Volitional Form
- Ichidan: stem + "yo(u)."
- Godan: final sound to "o" row + "u."
- Polite: stem + "mashou."
- Kuru: koyou; suru: shiyou.
Key Terms & Definitions
- Ichidan verb — A verb with simple conjugation, drop "ru" for forms.
- Godan verb — A verb with complex conjugation, final sound determines the ending.
- Dictionary form — The base, casual form of a verb.
- Verb stem — The root used for attaching grammatical endings.
- Te-form — Used for linking actions, making requests.
- Nai-form — Negative form.
- Ta-form — Past tense form.
- Masu-form — Polite form.
- Volitional form — Expresses intent or suggestion ("let's").
- Ba-form — Conditional "if/when" form.
- TARA-form — Conditional/temporal "if/when/after" form.
- Passive — Action done to the subject.
- Causative — To make/let someone do something.
- Potential — Ability to do something.
Action Items / Next Steps
- Practice identifying verb type using the nai-form method.
- Memorize endings for each conjugation, focusing on godan patterns.
- Review irregular verb forms for suru, kuru, and aru.
- Complete any workbook exercises on Japanese verb conjugations.