E04
core
Speaker stance
Modality
Obligation Aura
Must it happen? Is it required?
basic
Modal verb
Deontic modality
Obligation
意味
A modal layer expressing necessity, duty, rule, requirement, pressure, or unavoidable need.
見分け方
Ask whether someone has to do something.
例
単語
must|have to|need to|required
フレーズ
must leave|have to work|need to study
文
You have to finish this today.
Visual guide
Basic shape
Obligation layer:
[person] → [event]
↑
rule / duty / need
must / have to / need to
You have to finish this today.
Compare shape
Same force, many shapes: EN modal: must leave EN phrase: have to work Verb: need to study Impersonal: required Particle/suffix: WORK + OBLIG
言語別ビュー
母語の仕組み
日本語
表れ方
strong
重要度
Obligation often uses long negative-conditional style patterns such as なければならない.
今日これを終わらせなければならない。
I must finish this today.
学習言語では
英語
表れ方
strong
難易度
English obligation uses must, have to, need to, should, and be supposed to, with important nuance differences.
You must wear a seatbelt.
must = obligation
よくあるつまずき
Learners often confuse must, have to, should, and need to.
Same block, different coding
Both languages use this block strongly, but they signal it differently. Focus on form changes, not only meaning.