4.2 KiB
Obligation
が必要・必要がある
Means "needed" or "necessary". が{必要|ひつよう} is used mainly with nouns (can be used with verbs by appending こと before). {必要|ひつよう}がある is used with verbs.
[!info] Example {今時|いまどき}、{携帯電話|けいたいでんわ}==が必要です==。 Nowadays, a cell phone is necessary.
今日はパン{屋|や}に行く==必要がない==。 No need to go to the bakery today.
わけにはいかない
Used with verbs for a meaning of "cannot do" (which cannot be your inability, but an external factor). Used with verbs in negative form (ない) for a meaning of "cannot be avoided". Can be used as わけはいかない or わけにはいきません.
[!info] Example {今日|きょう}の{弟|おとうと}の{誕生日|たんじょうび}に行か==ないわけにはいかない==だから、{飲|の}み{会|かい}に行かない。 There's no way I don't go to my younger brother's birthday today, so I won't go to the afterwork.
{本当|ほんとう}に飲み会に行く==わけにはいかない==よ。 There's really no way I can go to the afterwork.
なくてもいい
Means "don't have to". Used with a verb in the negative form (ない), appending なくてもいい. Can also be used as なくていい.
[!info] Example 今日はレストランで{手伝|て|つ}わ==なくてもいい==。 You don't have to help out at the restaurant today (it's okay if you don't help at the restaurant today).
てからでないと
Means "must first do". The second part becomes possible after the first one. Used with a verb in て form, with からでないと or からでないければ.
[!info] Example {払|はら}==ってからでないと=={入|はい}るができること。 You can enter only after paying.
こと as "should do"
こと
V (dictionary)
V (ない)
+ こと
Means "should do". Mostly used to set rules.
[!info] Example ここに{車|くるま}を{止|と}めない==こと==です。 Don't park your car here.
ことになっている
This form is used to express rules or expectations. Used with dictionary (る) and negative (ない) form of verbs.
[!info] Examples {指|ゆび}で食べない==ことになっている==。 You're not supposed to eat with your fingers.
ことはない
This has two meanings:
- it is not necessary to
- it never happens
Used with a verb in the dictionary form.
[!info] Example {走|はし}る==ことはない==。まだ{時間|じかん}がある。 There's no need to run. There's still time.
必ず
{必|かなら}ず means certainly, definitely. Expresses an obligation.
[!info] Example 明日の{授業|じゅ|ぎょう}==必ず==来てください。 Please be sure to attend tomorrow's class.
べき
べきだ
Means "should do", "must do". Compared to the Obligation - なければ・ないと forms and 必ず, it has a nuance of being less universally logical. It is defined by the speaker's own logic. Used with verbs. する can be used as するべき or すべき.
[!info] Example {来週|らいしゅう}{試験|しけん}があるので{勉強|べんきょう}す==べきです==。 There is an exam next week, so I should study.
べきではない・べきじゃない
The contrary of べきだ is べきではない・べきじゃない.
[!info] Example {泥|どろ}を食べる==べきではない==。 You should not eat mud.
はずだ・はずがない
V
い-Adj
な-Adj + な
N + の
+ はずだ ・ はずがない
はずだ means "it must/should be", while はずがない means "it cannot be". Has a nuance of being sure that it is something possible (or impossible).
[!info] Examples {彼|かれ}は今日来る==はずだ==。 He should be coming today.
そんあ==はずがありません==。 This cannot be true.