With or Without A?

English for Today by Ganiu Abisoye Bamgbose (Dr GAB)

With or Without S?

She just came ~out of the blues~ and demanded a refund (nonstandard).
She just came out of the blue and demanded a refund (standard). If something happens out of the blue, it is completely unexpected.

~Back in the days~, students ate with chicken as undergraduates (nonstandard).
Back in the day, students ate with chicken as undergraduates (standard). The expression is used for talking about a time in the past, usually when you are remembering nice things about that time.

You shouldn’t ~rest on your laurel~ after a first degree (nonstandard).
You shouldn’t rest on your laurels after a first degree (standard). To rest on your laurels is to be satisfied with your achievements and not to make an effort to do anything else.
GAB