Formal Non-feasibility

Vocabulary

やるu-verbto do
事情(じじょう)じ・じょうcircumstances
認(みと)めるみと・めるru-verbto acknowledge
行(い)くい・くu-verbto go
言(い)うい・うu-verbto say
決定(けってい)けっ・ていdecision
延期(えんき)えん・きpostponement
説明(せつめい)せつ・めいexplanation
状況(じょうきょう)じょう・きょうsituation

Advanced ways to say “Cannot” or “Must”.

ざるを得(え)ない (Have no choice but to)

“It is not possible to not do…” → “I have to do it.”

Structure: Negative stem (drop ない) + ざるを得(え)ない

やらざるを得(え)ない。I have no choice but to do it.
認(みと)めざるを得(え)ない。I have no choice but to acknowledge it.
行(い)かざるを得(え)ない状況(じょうきょう)だ。It's a situation where I have no choice but to go.

Exception: する → せざるを得(え)ない

説明(せつめい)せざるを得(え)ない。I have no choice but to explain.

やむを得(え)ない (Unavoidable)

“It is unavoidable” / “It can’t be helped”

やむを得(え)ない事情(じじょう)で...Due to unavoidable circumstances...
やむを得(え)ない決定(けってい)だった。It was an unavoidable decision.
延期(えんき)はやむを得(え)ない。The postponement is unavoidable.

Polite form

やむを得(え)ません。It can't be helped. (polite)