How to differentiate between the meanings of けり?

Question

けり has 2 meanings: 過去 and 詠嘆. Is there some sort of trick to find out which one is being used? (besides context, of course)

Answer 1

• 詠嘆のけり is placed at the end of the main clause.
• 詠嘆のけり takes the 終止形 form unless 係り結び is involved.
• 詠嘆のけり appears more often in quotes than in narrative parts.
• なりけり is always 詠嘆.
• In haiku/waka, けり is almost always 詠嘆.

_{By the way, I feel 詠嘆のけり is somewhat close to 発見のタ in modern Japanese.}

References:

• 「き・けり」 - 古典文法
• 助動詞 けり の詠嘆と過去の見分け方おしえてください！