Definition: In Japanese the conjugation of verbs is more complicated than English, because in Japanese the conjugation in future and present is same but exit the past, negative, form i, form te, Potential, Causative, Passive causative, Imperative, Passive, Volitional, form conditionally eba, form conditionally ra.
In Japanese the present and future are same and the difference the put the context of time in where you have the talk, in these tenses is not necessary the conjugation.
Example:
Present: I eat fish = 私 は 魚 を 食 べ る = Watashi wa sakana o taberu
Future: I eat fish = 私 は 魚 を 食 べ る = Watashi wa sakana o taberu
For make this conjugation, you should do the replacement of the letters you see to below, this letters you find in finish the verbs or adjectives.
Present | Past |
す る = suru | し た = shita |
来 る = kuru | 来 た = kita |
行 く = iku | 行 っ た = itta |
い ら っ し ゃ る = irassharu | い ら っ し ゃ っ た = irasshatta |
ま す = masu | ま し た = mashita |
Present | Past |
う = u | っ た = tta |
く = ku | い た = ita |
ぐ = gu | い だ ida |
す = su | し た = shita |
つ = tsu | っ た = tta |
ぬ = nu | ん だ = nda |
ぶ = bu | ん だ = nda |
む = mu | ん だ = nda |
る = ru | っ た = tta |
い る = iru | い た = ita |
え る = eru | え た = eta |
Examples:
使 う = tsukau (Present)
使 っ た = tsukatta (Past)
泳 ぐ = oyogu* (Present)
泳 い だ = oyoida* (Past)
待 つ = matsu* (Present)
待 っ た = matta* (Past)
呼 ぶ = yobu* (Present)
呼 ん だ = yonda* (Past)
着 替 え る = kigaeru* (Present)
着 替 え た = kigaeta* (Past)
Present | Past |
い = i | か っ た = katta |
な = na | だ っ た = datta |
Examples:
安 い yasui*
安 か っ た yasukatta*
簡 単 kantan*
簡 単 だ っ た kantan datta*
The basic pattern is to convert u in nai or anai.
Infinitive | Negative |
す る = suru | し な い = shinai |
来 る = kuru | 来 な い = konai |
あ る = aru | な い = nai |
だ = da | じ ゃ な い = ja nai |
ま す = masu | ま せ ん = masen |
Examples:
勉 強 す る = benkyō suru*
勉 強 し な い = benkyō shinai*
行 き ま す = ikimasu*
行 き ま せ ん = ikimasen*
Infinitive | Negative |
う = u | わない = wanai |
く = ku | かない = kanai |
ぐ = gu | がない = ganai |
す = su | さない = sanai |
つ = tsu | たない = tanai |
ぬ = nu | なない = nanai |
ぶ = bu | ばない = banai |
む = mu | まない = manai |
る = ru | らない = ranai |
い る = iru | い な い = inai |
え る = eru | え な い = enai |
Examples:
待 つ = matsu*
待 た な い = matanai*
死 ぬ = shinu*
死 な な い = shinanai*
走 る = hashiru*
走 ら な い = hashiranai*
Present | Past |
い = i | く な い = kunai |
な = na | じ ゃ な い = ja nai |
Examples:
痛 い itai*
痛 く な い itakunai*
簡 単 kantan*
簡 単 じ ゃ な い kantan ja nai*