English for Today by Ganiu Abisoye Bamgbose (Dr GAB)
With or without articles
Kunle has an upper hand (nonstandard).
Kunle has the upper hand (standard). If you have the upper hand in a situation, you have more power than the other people involved and can make decisions about what happens. The definite article “the” is part of the idiom.
He has an experience in teaching English (nonstandard).
He has experience in teaching English (standard). When experience means practical contact with and observation of facts or events, it doesn’t attract plural marker.
Her room was in absolute shambles (nonstandard).
He room was in an absolute shambles (standard).
GAB

No comment