English for Today by Ganiu Abisoye Bamgbose
HANDLING ARTICLES
He gave ~an evidence~ for the action (nonstandard).
He gave evidence for the action (standard). The available body of facts or information indicating whether a belief or proposition is true or valid is called evidence.
Line the pots with pebbles to ensure ~a good drainage~ (nonstandard).
Line the pots with pebbles to ensure good drainage (standard).
Line the pots with pebbles to ensure a good drain (standard).
GAB

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