AnalyzerSentence analysis3SpansSentence勢いが衰える。1000 character limitAnalyzeSentence勢いきおいが衰おとろえる。Span Details勢いきおいforce; vigor; energy; power; influence; authority; momentum; impetus; impulse; inevitably; naturally; necessarilynoun, adverbがsubject markergrammar衰おとろえる。weaken; decline; waste awayichidan verb