Supposedly Plural Nouns without S

English for Today by Ganiu Abisoye Bamgbose (Dr GAB)

Supposedly plural nouns without S

No grammatical error escapes my eagle eyes (nonstandard).
No grammatical error escapes my eagle eye (standard). To keep a keen or close watch is to have an eagle eye.

An opposite sex shouldn’t sit on your laps in the class (nonstandard).
An opposite sex shouldn’t sit on your lap in the class (standard). The flat area between the waist and knees of a seated person is called lap.

Eat plenty of fresh fruits and vegetables (nonstandard).
Eat plenty of fresh fruit and vegetables (standard).

The children caught several fishes (nonstandard).
The children caught several fish (standard). However, fishes can be used when one means the different kinds of fish: All fishes can be eaten.
GAB